The functions given below are the ones which a user of PostGIS Raster is likely to need and which are currently available in PostGIS Raster. There are other functions which are required support functions to the raster objects which are not of use to a general user. raster is a new PostGIS type for storing and analyzing raster data. For loading rasters from raster files please refer to For the examples in this reference we will be using a raster table of dummy rasters - Formed with the following code CREATE TABLE dummy_rast(rid integer, rast raster); INSERT INTO dummy_rast(rid, rast) VALUES (1, ('01' -- little endian (uint8 ndr) || '0000' -- version (uint16 0) || '0000' -- nBands (uint16 0) || '0000000000000040' -- scaleX (float64 2) || '0000000000000840' -- scaleY (float64 3) || '000000000000E03F' -- ipX (float64 0.5) || '000000000000E03F' -- ipY (float64 0.5) || '0000000000000000' -- skewX (float64 0) || '0000000000000000' -- skewY (float64 0) || '00000000' -- SRID (int32 0) || '0A00' -- width (uint16 10) || '1400' -- height (uint16 20) )::raster ), -- Raster: 5 x 5 pixels, 3 bands, PT_8BUI pixel type, NODATA = 0 (2, ('01000003009A9999999999A93F9A9999999999A9BF000000E02B274A' || '41000000007719564100000000000000000000000000000000FFFFFFFF050005000400FDFEFDFEFEFDFEFEFDF9FAFEF' || 'EFCF9FBFDFEFEFDFCFAFEFEFE04004E627AADD16076B4F9FE6370A9F5FE59637AB0E54F58617087040046566487A1506CA2E3FA5A6CAFFBFE4D566DA4CB3E454C5665')::raster); This section lists the PostgreSQL data types specifically created to support raster functionality. geomval A spatial datatype with two fields - geom (holding a geometry object) and val (holding a double precision pixel value from a raster band). geomval is a compound data type consisting of a geometry object referenced by the .geom field and val, a double precision value that represents the pixel value at a particular geometric location in a raster band. It is used by the ST_DumpAsPolygon and Raster intersection family of functions as an output type to explode a raster band into geometry polygons. addbandarg A composite type used as input into the ST_AddBand function defining the attributes and initial value of the new band. A composite type used as input into the ST_AddBand function defining the attributes and initial value of the new band. index integer 1-based value indicating the position where the new band will be added amongst the raster's bands. If NULL, the new band will be added at the end of the raster's bands. pixeltype text Pixel type of the new band. One of defined pixel types as described in . initialvalue double precision Initial value that all pixels of new band will be set to. nodataval double precision NODATA value of the new band. If NULL, the new band will not have a NODATA value assigned. rastbandarg A composite type for use when needing to express a raster and a band index of that raster. A composite type for use when needing to express a raster and a band index of that raster. rast raster The raster in question/ nband integer 1-based value indicating the band of raster raster raster spatial data type. raster is a spatial data type used to represent raster data such as those imported from jpegs, tiffs, pngs, digital elevation models. Each raster has 1 or more bands each having a set of pixel values. Rasters can be georeferenced. Requires PostGIS be compiled with GDAL support. Currently rasters can be implicitly converted to geometry type, but the conversion returns the of the raster. This auto casting may be removed in the near future so don't rely on it. This section lists the automatic as well as explicit casts allowed for this data type Cast To Behavior geometry automatic reclassarg A composite type used as input into the ST_Reclass function defining the behavior of reclassification. A composite type used as input into the ST_Reclass function defining the behavior of reclassification. nband integer The band number of band to reclassify. reclassexpr text range expression consisting of comma delimited range:map_range mappings. : to define mapping that defines how to map old band values to new band values. ( means >, ) means less than, ] < or equal, [ means > or equal 1. [a-b] = a <= x <= b 2. (a-b] = a < x <= b 3. [a-b) = a <= x < b 4. (a-b) = a < x < b ( notation is optional so a-b means the same as (a-b) pixeltype text One of defined pixel types as described in nodataval double precision Value to treat as no data. For image outputs that support transparency, these will be blank. SELECT ROW(2, '0-100:1-10, 101-500:11-150,501 - 10000: 151-254', '8BUI', 255)::reclassarg; SELECT ROW(1, '0-100]:0, (100-255:1', '1BB', NULL)::reclassarg; summarystats A composite type returned by the ST_SummaryStats and ST_SummaryStatsAgg functions. A composite type returned by the and functions. count integer Number of pixels counted for the summary statistics. sum double precision Sum of all counted pixel values. mean double precision Arithmetic mean of all counted pixel values. stddev double precision Standard deviation of all counted pixel values. min double precision Minimum value of counted pixel values. max double precision Maximum value of counted pixel values. , unionarg A composite type used as input into the ST_Union function defining the bands to be processed and behavior of the UNION operation. A composite type used as input into the ST_Union function defining the bands to be processed and behavior of the UNION operation. nband integer 1-based value indicating the band of each input raster to be processed. uniontype text Type of UNION operation. One of defined types as described in . AddRasterConstraints Adds raster constraints to a loaded raster table for a specific column that constrains spatial ref, scaling, blocksize, alignment, bands, band type and a flag to denote if raster column is regularly blocked. The table must be loaded with data for the constraints to be inferred. Returns true of the constraint setting was accomplished and if issues a notice. boolean AddRasterConstraints name rasttable name rastcolumn boolean srid boolean scale_x boolean scale_y boolean blocksize_x boolean blocksize_y boolean same_alignment boolean regular_blocking boolean num_bands=true boolean pixel_types=true boolean nodata_values=true boolean out_db=true boolean extent=true boolean AddRasterConstraints name rasttable name rastcolumn text[] VARIADIC constraints boolean AddRasterConstraints name rastschema name rasttable name rastcolumn text[] VARIADIC constraints boolean AddRasterConstraints name rastschema name rasttable name rastcolumn boolean srid=true boolean scale_x=true boolean scale_y=true boolean blocksize_x=true boolean blocksize_y=true boolean same_alignment=true boolean regular_blocking=false boolean num_bands=true boolean pixel_types=true boolean nodata_values=true boolean out_db=true boolean extent=true Generates constraints on a raster column that are used to display information in the raster_columns raster catalog. The rastschema is the name of the table schema the table resides in. The srid must be an integer value reference to an entry in the SPATIAL_REF_SYS table. raster2pgsql loader uses this function to register raster tables Valid constraint names to pass in: refer to for more details. blocksize sets both X and Y blocksize blocksize_x sets X tile (width in pixels of each tile) blocksize_y sets Y tile (height in pixels of each tile) extent computes extent of whole table and applys constraint all rasters must be within that extent num_bands number of bands pixel_types reads array of pixel types for each band ensure all band n have same pixel type regular_blocking sets spatially unique (no two rasters can be spatially the same) and coverage tile (raster is aligned to a coverage) constraints same_alignment ensures they all have same alignment meaning any two tiles you compare will return true for. Refer to srid ensures all have same srid More -- any listed as inputs into the above functions This function infers the constraints from the data already present in the table. As such for it to work, you must create the raster column first and then load it with data. If you need to load more data in your tables after you have already applied constraints, you may want to run the DropRasterConstraints if the extent of your data has changed. Availability: 2.0.0 CREATE TABLE myrasters(rid SERIAL primary key, rast raster); INSERT INTO myrasters(rast) SELECT ST_AddBand(ST_MakeEmptyRaster(1000, 1000, 0.3, -0.3, 2, 2, 0, 0,4326), 1, '8BSI'::text, -129, NULL); SELECT AddRasterConstraints('myrasters'::name, 'rast'::name); -- verify if registered correctly in the raster_columns view -- SELECT srid, scale_x, scale_y, blocksize_x, blocksize_y, num_bands, pixel_types, nodata_values FROM raster_columns WHERE r_table_name = 'myrasters'; srid | scale_x | scale_y | blocksize_x | blocksize_y | num_bands | pixel_types| nodata_values ------+---------+---------+-------------+-------------+-----------+-------------+--------------- 4326 | 2 | 2 | 1000 | 1000 | 1 | {8BSI} | {0} CREATE TABLE public.myrasters2(rid SERIAL primary key, rast raster); INSERT INTO myrasters2(rast) SELECT ST_AddBand(ST_MakeEmptyRaster(1000, 1000, 0.3, -0.3, 2, 2, 0, 0,4326), 1, '8BSI'::text, -129, NULL); SELECT AddRasterConstraints('public'::name, 'myrasters2'::name, 'rast'::name,'regular_blocking', 'blocksize'); -- get notice-- NOTICE: Adding regular blocking constraint NOTICE: Adding blocksize-X constraint NOTICE: Adding blocksize-Y constraint , , , , , DropRasterConstraints Drops PostGIS raster constraints that refer to a raster table column. Useful if you need to reload data or update your raster column data. boolean DropRasterConstraints name rasttable name rastcolumn boolean srid boolean scale_x boolean scale_y boolean blocksize_x boolean blocksize_y boolean same_alignment boolean regular_blocking boolean num_bands=true boolean pixel_types=true boolean nodata_values=true boolean out_db=true boolean extent=true boolean DropRasterConstraints name rastschema name rasttable name rastcolumn boolean srid=true boolean scale_x=true boolean scale_y=true boolean blocksize_x=true boolean blocksize_y=true boolean same_alignment=true boolean regular_blocking=false boolean num_bands=true boolean pixel_types=true boolean nodata_values=true boolean out_db=true boolean extent=true boolean DropRasterConstraints name rastschema name rasttable name rastcolumn text[] constraints Drops PostGIS raster constraints that refer to a raster table column that were added by . Useful if you need to load more data or update your raster column data. You do not need to do this if you want to get rid of a raster table or a raster column. To drop a raster table use the standard DROP TABLE mytable To drop just a raster column and leave the rest of the table, use standard SQL ALTER TABLE mytable DROP COLUMN rast the table will disappear from the raster_columns catalog if the column or table is dropped. However if only the constraints are dropped, the raster column will still be listed in the raster_columns catalog, but there will be no other information about it aside from the column name and table. Availability: 2.0.0 SELECT DropRasterConstraints ('myrasters','rast'); ----RESULT output --- t -- verify change in raster_columns -- SELECT srid, scale_x, scale_y, blocksize_x, blocksize_y, num_bands, pixel_types, nodata_values FROM raster_columns WHERE r_table_name = 'myrasters'; srid | scale_x | scale_y | blocksize_x | blocksize_y | num_bands | pixel_types| nodata_values ------+---------+---------+-------------+-------------+-----------+-------------+--------------- 0 | | | | | | | AddOverviewConstraints Tag a raster column as being an overview of another. boolean AddOverviewConstraints name ovschema name ovtable name ovcolumn name refschema name reftable name refcolumn int ovfactor boolean AddOverviewConstraints name ovtable name ovcolumn name reftable name refcolumn int ovfactor Adds constraints on a raster column that are used to display information in the raster_overviews raster catalog. The ovfactor parameter represents the scale multiplier in the overview column: higher overview factors have lower resolution. When the ovschema and refschema parameters are omitted, the first table found scanning the search_path will be used. Availability: 2.0.0 CREATE TABLE res1 AS SELECT ST_AddBand( ST_MakeEmptyRaster(1000, 1000, 0, 0, 2), 1, '8BSI'::text, -129, NULL ) r1; CREATE TABLE res2 AS SELECT ST_AddBand( ST_MakeEmptyRaster(500, 500, 0, 0, 4), 1, '8BSI'::text, -129, NULL ) r2; SELECT AddOverviewConstraints('res2', 'r2', 'res1', 'r1', 2); -- verify if registered correctly in the raster_overviews view -- SELECT o_table_name ot, o_raster_column oc, r_table_name rt, r_raster_column rc, overview_factor f FROM raster_overviews WHERE o_table_name = 'res2'; ot | oc | rt | rc | f ------+----+------+----+--- res2 | r2 | res1 | r1 | 2 (1 row) , , , DropOverviewConstraints Untag a raster column from being an overview of another. boolean DropOverviewConstraints name ovschema name ovtable name ovcolumn boolean DropOverviewConstraints name ovtable name ovcolumn Remove from a raster column the constraints used to show it as being an overview of another in the raster_overviews raster catalog. When the ovschema parameter is omitted, the first table found scanning the search_path will be used. Availability: 2.0.0 , , PostGIS_GDAL_Version Reports the version of the GDAL library in use by PostGIS. text PostGIS_GDAL_Version Reports the version of the GDAL library in use by PostGIS. Will also check and report if GDAL can find its data files. SELECT PostGIS_GDAL_Version(); postgis_gdal_version ----------------------------------- GDAL 1.11dev, released 2013/04/13 PostGIS_Raster_Lib_Build_Date Reports full raster library build date. text PostGIS_Raster_Lib_Build_Date Reports raster build date SELECT PostGIS_Raster_Lib_Build_Date(); postgis_raster_lib_build_date ----------------------------- 2010-04-28 21:15:10 PostGIS_Raster_Lib_Version Reports full raster version and build configuration infos. text PostGIS_Raster_Lib_Version Reports full raster version and build configuration infos. SELECT PostGIS_Raster_Lib_Version(); postgis_raster_lib_version ----------------------------- 2.0.0 ST_GDALDrivers Returns a list of raster formats supported by your lib gdal. These are the formats you can output your raster using ST_AsGDALRaster. setof record ST_GDALDrivers integer OUT idx text OUT short_name text OUT long_name text OUT create_options Returns a list of raster formats short_name,long_name and creator options of each format supported by your lib gdal. Use the short_name as input in the format parameter of . Options vary depending on what drivers your libgdal was compiled with. create_options returns an xml formatted set of CreationOptionList/Option consisting of name and optional type, description and set of VALUE for each creator option for the specific driver. Availability: 2.0.0 - requires GDAL >= 1.6.0. SELECT short_name, long_name FROM st_gdaldrivers() ORDER BY short_name; short_name | long_name ----------------+-------------------------------------- AAIGrid | Arc/Info ASCII Grid DTED | DTED Elevation Raster EHdr | ESRI .hdr Labelled FIT | FIT Image GIF | Graphics Interchange Format (.gif) GSAG | Golden Software ASCII Grid (.grd) GSBG | Golden Software Binary Grid (.grd) GTiff | GeoTIFF HF2 | HF2/HFZ heightfield raster HFA | Erdas Imagine Images (.img) ILWIS | ILWIS Raster Map INGR | Intergraph Raster JPEG | JPEG JFIF KMLSUPEROVERLAY | Kml Super Overlay NITF | National Imagery Transmission Format PNG | Portable Network Graphics R | R Object Data Store SAGA | SAGA GIS Binary Grid (.sdat) SRTMHGT | SRTMHGT File Format USGSDEM | USGS Optional ASCII DEM (and CDED) VRT | Virtual Raster XPM | X11 PixMap Format -- Output the create options XML column of JPEG as a table -- -- Note you can use these creator options in ST_AsGDALRaster options argument SELECT (xpath('@name', g.opt))[1]::text As oname, (xpath('@type', g.opt))[1]::text As otype, (xpath('@description', g.opt))[1]::text As descrip FROM (SELECT unnest(xpath('/CreationOptionList/Option', create_options::xml)) As opt FROM st_gdaldrivers() WHERE short_name = 'JPEG') As g; oname | otype | descrip -------------+---------+----------------------------- PROGRESSIVE | boolean | QUALITY | int | good=100, bad=0, default=75 WORLDFILE | boolean | -- raw xml output for creator options for GeoTiff -- SELECT create_options FROM st_gdaldrivers() WHERE short_name = 'GTiff'; NONE LZW PACKBITS JPEG CCITTRLE CCITTFAX3 CCITTFAX4 DEFLATE BAND PIXEL MINISBLACK MINISWHITE PALETTE RGB CMYK YCBCR CIELAB ICCLAB ITULAB GDALGeoTIFF GeoTIFF BASELINE DEFAULT SIGNEDBYTE YES NO IF_NEEDED IF_SAFER NATIVE INVERTED LITTLE BIG ]]> -- Output the create options XML column for GTiff as a table -- SELECT (xpath('@name', g.opt))[1]::text As oname, (xpath('@type', g.opt))[1]::text As otype, (xpath('@description', g.opt))[1]::text As descrip, array_to_string(xpath('Value/text()', g.opt),', ') As vals FROM (SELECT unnest(xpath('/CreationOptionList/Option', create_options::xml)) As opt FROM st_gdaldrivers() WHERE short_name = 'GTiff') As g; oname | otype | descrip | vals --------------------+---------------+----------------------------------------------------------------------+--------------------------------------------------------------------------- COMPRESS | string-select | | NONE, LZW, PACKBITS, JPEG, CCITTRLE, CCITTFAX3, CCITTFAX4, DEFLATE PREDICTOR | int | Predictor Type | JPEG_QUALITY | int | JPEG quality 1-100 | ZLEVEL | int | DEFLATE compression level 1-9 | NBITS | int | BITS for sub-byte files (1-7), sub-uint16 (9-15), sub-uint32 (17-31) | INTERLEAVE | string-select | | BAND, PIXEL TILED | boolean | Switch to tiled format | TFW | boolean | Write out world file | RPB | boolean | Write out .RPB (RPC) file | BLOCKXSIZE | int | Tile Width | BLOCKYSIZE | int | Tile/Strip Height | PHOTOMETRIC | string-select | | MINISBLACK, MINISWHITE, PALETTE, RGB, CMYK, YCBCR, CIELAB, ICCLAB, ITULAB SPARSE_OK | boolean | Can newly created files have missing blocks? | ALPHA | boolean | Mark first extrasample as being alpha | PROFILE | string-select | | GDALGeoTIFF, GeoTIFF, BASELINE PIXELTYPE | string-select | | DEFAULT, SIGNEDBYTE BIGTIFF | string-select | Force creation of BigTIFF file | YES, NO, IF_NEEDED, IF_SAFER ENDIANNESS | string-select | Force endianness of created file. For DEBUG purpose mostly | NATIVE, INVERTED, LITTLE, BIG COPY_SRC_OVERVIEWS | boolean | Force copy of overviews of source dataset (CreateCopy()) | (19 rows) , UpdateRasterSRID Change the SRID of all rasters in the user-specified column and table. raster UpdateRasterSRID name schema_name name table_name name column_name integer new_srid raster UpdateRasterSRID name table_name name column_name integer new_srid Change the SRID of all rasters in the user-specified column and table. The function will drop all appropriate column constraints (extent, alignment and SRID) before changing the SRID of the specified column's rasters. The data (band pixel values) of the rasters are not touched by this function. Only the raster's metadata is changed. Availability: 2.1.0 ST_CreateOverview Create an reduced resolution version of a given raster coverage. regclass ST_CreateOverview regclass tab name col int factor text algo='NearestNeighbor' Create an overview table with resampled tiles from the source table. Output tiles will have the same size of input tiles and cover the same spatial extent with a lower resolution (pixel size will be 1/factor of the original in both directions). The overview table will be made available in the raster_overviews catalog and will have raster constraints enforced. Algorithm options are: 'NearestNeighbor', 'Bilinear', 'Cubic', 'CubicSpline', and 'Lanczos'. Refer to: GDAL Warp resampling methods for more details. Availability: 2.2.0 , , , ST_AddBand Returns a raster with the new band(s) of given type added with given initial value in the given index location. If no index is specified, the band is added to the end. (1) raster ST_AddBand raster rast addbandarg[] addbandargset (2) raster ST_AddBand raster rast integer index text pixeltype double precision initialvalue=0 double precision nodataval=NULL (3) raster ST_AddBand raster rast text pixeltype double precision initialvalue=0 double precision nodataval=NULL (4) raster ST_AddBand raster torast raster fromrast integer fromband=1 integer torastindex=at_end (5) raster ST_AddBand raster torast raster[] fromrasts integer fromband=1 integer torastindex=at_end (6) raster ST_AddBand raster rast integer index text outdbfile integer[] outdbindex double precision nodataval=NULL (7) raster ST_AddBand raster rast text outdbfile integer[] outdbindex integer index=at_end double precision nodataval=NULL Returns a raster with a new band added in given position (index), of given type, of given initial value, and of given nodata value. If no index is specified, the band is added to the end. If no fromband is specified, band 1 is assumed. Pixel type is a string representation of one of the pixel types specified in . If an existing index is specified all subsequent bands >= that index are incremented by 1. If an initial value greater than the max of the pixel type is specified, then the initial value is set to the highest value allowed by the pixel type. For the variant that takes an array of (Variant 1), a specific addbandarg's index value is relative to the raster at the time when the band described by that addbandarg is being added to the raster. See the Multiple New Bands example below. For the variant that takes an array of rasters (Variant 5), if torast is NULL then the fromband band of each raster in the array is accumulated into a new raster. For the variants that take outdbfile (Variants 6 and 7), the value must include the full path to the raster file. The file must also be accessible to the postgres server process. Enhanced: 2.1.0 support for addbandarg added. Enhanced: 2.1.0 support for new out-db bands added. -- Add another band of type 8 bit unsigned integer with pixels initialized to 200 UPDATE dummy_rast SET rast = ST_AddBand(rast,'8BUI'::text,200) WHERE rid = 1; -- Create an empty raster 100x100 units, with upper left right at 0, add 2 bands (band 1 is 0/1 boolean bit switch, band2 allows values 0-15) -- uses addbandargs INSERT INTO dummy_rast(rid,rast) VALUES(10, ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 1, -1, 0, 0, 0), ARRAY[ ROW(1, '1BB'::text, 0, NULL), ROW(2, '4BUI'::text, 0, NULL) ]::addbandarg[] ) ); -- output meta data of raster bands to verify all is right -- SELECT (bmd).* FROM (SELECT ST_BandMetaData(rast,generate_series(1,2)) As bmd FROM dummy_rast WHERE rid = 10) AS foo; --result -- pixeltype | nodatavalue | isoutdb | path -----------+----------------+-------------+---------+------ 1BB | | f | 4BUI | | f | -- output meta data of raster - SELECT (rmd).width, (rmd).height, (rmd).numbands FROM (SELECT ST_MetaData(rast) As rmd FROM dummy_rast WHERE rid = 10) AS foo; -- result -- upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands ------------+------------+-------+--------+------------+------------+-------+-------+------+---------- 0 | 0 | 100 | 100 | 1 | -1 | 0 | 0 | 0 | 2 SELECT * FROM ST_BandMetadata( ST_AddBand( ST_MakeEmptyRaster(10, 10, 0, 0, 1, -1, 0, 0, 0), ARRAY[ ROW(NULL, '8BUI', 255, 0), ROW(NULL, '16BUI', 1, 2), ROW(2, '32BUI', 100, 12), ROW(2, '32BF', 3.14, -1) ]::addbandarg[] ), ARRAY[]::integer[] ); bandnum | pixeltype | nodatavalue | isoutdb | path ---------+-----------+-------------+---------+------ 1 | 8BUI | 0 | f | 2 | 32BF | -1 | f | 3 | 32BUI | 12 | f | 4 | 16BUI | 2 | f | -- Aggregate the 1st band of a table of like rasters into a single raster -- with as many bands as there are test_types and as many rows (new rasters) as there are mice -- NOTE: The ORDER BY test_type is only supported in PostgreSQL 9.0+ -- for 8.4 and below it usually works to order your data in a subselect (but not guaranteed) -- The resulting raster will have a band for each test_type alphabetical by test_type -- For mouse lovers: No mice were harmed in this exercise SELECT mouse, ST_AddBand(NULL, array_agg(rast ORDER BY test_type), 1) As rast FROM mice_studies GROUP BY mouse; SELECT * FROM ST_BandMetadata( ST_AddBand( ST_MakeEmptyRaster(10, 10, 0, 0, 1, -1, 0, 0, 0), '/home/raster/mytestraster.tif'::text, NULL::int[] ), ARRAY[]::integer[] ); bandnum | pixeltype | nodatavalue | isoutdb | path ---------+-----------+-------------+---------+------ 1 | 8BUI | | t | /home/raster/mytestraster.tif 2 | 8BUI | | t | /home/raster/mytestraster.tif 3 | 8BUI | | t | /home/raster/mytestraster.tif , , , , , ST_AsRaster Converts a PostGIS geometry to a PostGIS raster. raster ST_AsRaster geometry geom raster ref text pixeltype double precision value=1 double precision nodataval=0 boolean touched=false raster ST_AsRaster geometry geom raster ref text[] pixeltype=ARRAY['8BUI'] double precision[] value=ARRAY[1] double precision[] nodataval=ARRAY[0] boolean touched=false raster ST_AsRaster geometry geom double precision scalex double precision scaley double precision gridx double precision gridy text pixeltype double precision value=1 double precision nodataval=0 double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom double precision scalex double precision scaley double precision gridx=NULL double precision gridy=NULL text[] pixeltype=ARRAY['8BUI'] double precision[] value=ARRAY[1] double precision[] nodataval=ARRAY[0] double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom double precision scalex double precision scaley text pixeltype double precision value=1 double precision nodataval=0 double precision upperleftx=NULL double precision upperlefty=NULL double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom double precision scalex double precision scaley text[] pixeltype double precision[] value=ARRAY[1] double precision[] nodataval=ARRAY[0] double precision upperleftx=NULL double precision upperlefty=NULL double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom integer width integer height double precision gridx double precision gridy text pixeltype double precision value=1 double precision nodataval=0 double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom integer width integer height double precision gridx=NULL double precision gridy=NULL text[] pixeltype=ARRAY['8BUI'] double precision[] value=ARRAY[1] double precision[] nodataval=ARRAY[0] double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom integer width integer height text pixeltype double precision value=1 double precision nodataval=0 double precision upperleftx=NULL double precision upperlefty=NULL double precision skewx=0 double precision skewy=0 boolean touched=false raster ST_AsRaster geometry geom integer width integer height text[] pixeltype double precision[] value=ARRAY[1] double precision[] nodataval=ARRAY[0] double precision upperleftx=NULL double precision upperlefty=NULL double precision skewx=0 double precision skewy=0 boolean touched=false Converts a PostGIS geometry to a PostGIS raster. The many variants offers three groups of possibilities for setting the alignment and pixelsize of the resulting raster. The first group, composed of the two first variants, produce a raster having the same alignment (scalex, scaley, gridx and gridy), pixel type and nodata value as the provided reference raster. You generally pass this reference raster by joining the table containing the geometry with the table containing the reference raster. The second group, composed of four variants, let you set the dimensions of the raster by providing the parameters of a pixel size (scalex & scaley and skewx & skewy). The width & height of the resulting raster will be adjusted to fit the extent of the geometry. In most cases, you must cast integer scalex & scaley arguments to double precision so that PostgreSQL choose the right variant. The third group, composed of four variants, let you fix the dimensions of the raster by providing the dimensions of the raster (width & height). The parameters of the pixel size (scalex & scaley and skewx & skewy) of the resulting raster will be adjusted to fit the extent of the geometry. The two first variants of each of those two last groups let you specify the alignment with an arbitrary corner of the alignment grid (gridx & gridy) and the two last variants takes the upper left corner (upperleftx & upperlefty). Each group of variant allows producing a one band raster or a multiple bands raster. To produce a multiple bands raster, you must provide an array of pixel types (pixeltype[]), an array of initial values (value) and an array of nodata values (nodataval). If not provided pixeltyped defaults to 8BUI, values to 1 and nodataval to 0. The output raster will be in the same spatial reference as the source geometry. The only exception is for variants with a reference raster. In this case the resulting raster will get the same SRID as the reference raster. The optional touched parameter defaults to false and maps to the GDAL ALL_TOUCHED rasterization option, which determines if pixels touched by lines or polygons will be burned. Not just those on the line render path, or whose center point is within the polygon. This is particularly useful for rendering jpegs and pngs of geometries directly from the database when using in combination with and other family of functions. Availability: 2.0.0 - requires GDAL >= 1.6.0. Not yet capable of rendering complex geometry types such as curves, TINS, and PolyhedralSurfaces, but should be able too once GDAL can. black circle -- this will output a black circle taking up 150 x 150 pixels -- SELECT ST_AsPNG(ST_AsRaster(ST_Buffer(ST_Point(1,5),10),150, 150, '2BUI')); example from buffer rendered with just PostGIS -- the bands map to RGB bands - the value (118,154,118) - teal -- SELECT ST_AsPNG( ST_AsRaster( ST_Buffer( ST_GeomFromText('LINESTRING(50 50,150 150,150 50)'), 10,'join=bevel'), 200,200,ARRAY['8BUI', '8BUI', '8BUI'], ARRAY[118,154,118], ARRAY[0,0,0])); , , , , , , ST_Band Returns one or more bands of an existing raster as a new raster. Useful for building new rasters from existing rasters. raster ST_Band raster rast integer[] nbands = ARRAY[1] raster ST_Band raster rast integer nband raster ST_Band raster rast text nbands character delimiter=, Returns one or more bands of an existing raster as a new raster. Useful for building new rasters from existing rasters or export of only selected bands of a raster or rearranging the order of bands in a raster. If no band is specified, band 1 is assumed. Used as a helper function in various functions such as for deleting a band. For the nbands as text variant of function, the default delimiter is , which means you can ask for '1,2,3' and if you wanted to use a different delimeter you would do ST_Band(rast, '1@2@3', '@'). For asking for multiple bands, we strongly suggest you use the array form of this function e.g. ST_Band(rast, '{1,2,3}'::int[]); since the text list of bands form may be removed in future versions of PostGIS. Availability: 2.0.0 -- Make 2 new rasters: 1 containing band 1 of dummy, second containing band 2 of dummy and then reclassified as a 2BUI SELECT ST_NumBands(rast1) As numb1, ST_BandPixelType(rast1) As pix1, ST_NumBands(rast2) As numb2, ST_BandPixelType(rast2) As pix2 FROM ( SELECT ST_Band(rast) As rast1, ST_Reclass(ST_Band(rast,3), '100-200):1, [200-254:2', '2BUI') As rast2 FROM dummy_rast WHERE rid = 2) As foo; numb1 | pix1 | numb2 | pix2 -------+------+-------+------ 1 | 8BUI | 1 | 2BUI -- Return bands 2 and 3. Using array cast syntax SELECT ST_NumBands(ST_Band(rast, '{2,3}'::int[])) As num_bands FROM dummy_rast WHERE rid=2; num_bands ---------- 2 -- Return bands 2 and 3. Use array to define bands SELECT ST_NumBands(ST_Band(rast, ARRAY[2,3])) As num_bands FROM dummy_rast WHERE rid=2; original (column rast) dupe_band sing_band --Make a new raster with 2nd band of original and 1st band repeated twice, and another with just the third band SELECT rast, ST_Band(rast, ARRAY[2,1,1]) As dupe_band, ST_Band(rast, 3) As sing_band FROM samples.than_chunked WHERE rid=35; , , , ST_MakeEmptyRaster Returns an empty raster (having no bands) of given dimensions (width & height), upperleft X and Y, pixel size and rotation (scalex, scaley, skewx & skewy) and reference system (srid). If a raster is passed in, returns a new raster with the same size, alignment and SRID. If srid is left out, the spatial ref is set to unknown (0). raster ST_MakeEmptyRaster raster rast raster ST_MakeEmptyRaster integer width integer height float8 upperleftx float8 upperlefty float8 scalex float8 scaley float8 skewx float8 skewy integer srid=unknown raster ST_MakeEmptyRaster integer width integer height float8 upperleftx float8 upperlefty float8 pixelsize Returns an empty raster (having no band) of given dimensions (width & height) and georeferenced in spatial (or world) coordinates with upper left X (upperleftx), upper left Y (upperlefty), pixel size and rotation (scalex, scaley, skewx & skewy) and reference system (srid). The last version use a single parameter to specify the pixel size (pixelsize). scalex is set to this argument and scaley is set to the negative value of this argument. skewx and skewy are set to 0. If an existing raster is passed in, it returns a new raster with the same meta data settings (without the bands). If no srid is specified it defaults to 0. After you create an empty raster you probably want to add bands to it and maybe edit it. Refer to to define bands and to set initial pixel values. INSERT INTO dummy_rast(rid,rast) VALUES(3, ST_MakeEmptyRaster( 100, 100, 0.0005, 0.0005, 1, 1, 0, 0, 4326) ); --use an existing raster as template for new raster INSERT INTO dummy_rast(rid,rast) SELECT 4, ST_MakeEmptyRaster(rast) FROM dummy_rast WHERE rid = 3; -- output meta data of rasters we just added SELECT rid, (md).* FROM (SELECT rid, ST_MetaData(rast) As md FROM dummy_rast WHERE rid IN(3,4)) As foo; -- output -- rid | upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands -----+------------+------------+-------+--------+------------+------------+-------+-------+------+---------- 3 | 0.0005 | 0.0005 | 100 | 100 | 1 | 1 | 0 | 0 | 4326 | 0 4 | 0.0005 | 0.0005 | 100 | 100 | 1 | 1 | 0 | 0 | 4326 | 0 , , , , , , , ST_Tile Returns a set of rasters resulting from the split of the input raster based upon the desired dimensions of the output rasters. setof raster ST_Tile raster rast int[] nband integer width integer height boolean padwithnodata=FALSE double precision nodataval=NULL setof raster ST_Tile raster rast integer nband integer width integer height boolean padwithnodata=FALSE double precision nodataval=NULL setof raster ST_Tile raster rast integer width integer height boolean padwithnodata=FALSE double precision nodataval=NULL Returns a set of rasters resulting from the split of the input raster based upon the desired dimensions of the output rasters. If padwithnodata = FALSE, edge tiles on the right and bottom sides of the raster may have different dimensions than the rest of the tiles. If padwithnodata = TRUE, all tiles will have the same dimensions with the possibilty that edge tiles being padded with NODATA values. If raster band(s) do not have NODATA value(s) specified, one can be specified by setting nodataval. If a specified band of the input raster is out-of-db, the corresponding band in the output rasters will also be out-of-db. Availability: 2.1.0 WITH foo AS ( SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '8BUI', 10, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, 0, 1, -1, 0, 0, 0), 1, '8BUI', 2, 0), 2, '8BUI', 20, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, 0, 1, -1, 0, 0, 0), 1, '8BUI', 3, 0), 2, '8BUI', 30, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -3, 1, -1, 0, 0, 0), 1, '8BUI', 4, 0), 2, '8BUI', 40, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -3, 1, -1, 0, 0, 0), 1, '8BUI', 5, 0), 2, '8BUI', 50, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -3, 1, -1, 0, 0, 0), 1, '8BUI', 6, 0), 2, '8BUI', 60, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -6, 1, -1, 0, 0, 0), 1, '8BUI', 7, 0), 2, '8BUI', 70, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -6, 1, -1, 0, 0, 0), 1, '8BUI', 8, 0), 2, '8BUI', 80, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -6, 1, -1, 0, 0, 0), 1, '8BUI', 9, 0), 2, '8BUI', 90, 0) AS rast ), bar AS ( SELECT ST_Union(rast) AS rast FROM foo ), baz AS ( SELECT ST_Tile(rast, 3, 3, TRUE) AS rast FROM bar ) SELECT ST_DumpValues(rast) FROM baz; st_dumpvalues ------------------------------------------ (1,"{{1,1,1},{1,1,1},{1,1,1}}") (2,"{{10,10,10},{10,10,10},{10,10,10}}") (1,"{{2,2,2},{2,2,2},{2,2,2}}") (2,"{{20,20,20},{20,20,20},{20,20,20}}") (1,"{{3,3,3},{3,3,3},{3,3,3}}") (2,"{{30,30,30},{30,30,30},{30,30,30}}") (1,"{{4,4,4},{4,4,4},{4,4,4}}") (2,"{{40,40,40},{40,40,40},{40,40,40}}") (1,"{{5,5,5},{5,5,5},{5,5,5}}") (2,"{{50,50,50},{50,50,50},{50,50,50}}") (1,"{{6,6,6},{6,6,6},{6,6,6}}") (2,"{{60,60,60},{60,60,60},{60,60,60}}") (1,"{{7,7,7},{7,7,7},{7,7,7}}") (2,"{{70,70,70},{70,70,70},{70,70,70}}") (1,"{{8,8,8},{8,8,8},{8,8,8}}") (2,"{{80,80,80},{80,80,80},{80,80,80}}") (1,"{{9,9,9},{9,9,9},{9,9,9}}") (2,"{{90,90,90},{90,90,90},{90,90,90}}") (18 rows) WITH foo AS ( SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '8BUI', 10, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, 0, 1, -1, 0, 0, 0), 1, '8BUI', 2, 0), 2, '8BUI', 20, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, 0, 1, -1, 0, 0, 0), 1, '8BUI', 3, 0), 2, '8BUI', 30, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -3, 1, -1, 0, 0, 0), 1, '8BUI', 4, 0), 2, '8BUI', 40, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -3, 1, -1, 0, 0, 0), 1, '8BUI', 5, 0), 2, '8BUI', 50, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -3, 1, -1, 0, 0, 0), 1, '8BUI', 6, 0), 2, '8BUI', 60, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, -6, 1, -1, 0, 0, 0), 1, '8BUI', 7, 0), 2, '8BUI', 70, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 3, -6, 1, -1, 0, 0, 0), 1, '8BUI', 8, 0), 2, '8BUI', 80, 0) AS rast UNION ALL SELECT ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 6, -6, 1, -1, 0, 0, 0), 1, '8BUI', 9, 0), 2, '8BUI', 90, 0) AS rast ), bar AS ( SELECT ST_Union(rast) AS rast FROM foo ), baz AS ( SELECT ST_Tile(rast, 3, 3, 2) AS rast FROM bar ) SELECT ST_DumpValues(rast) FROM baz; st_dumpvalues ------------------------------------------ (1,"{{10,10,10},{10,10,10},{10,10,10}}") (1,"{{20,20,20},{20,20,20},{20,20,20}}") (1,"{{30,30,30},{30,30,30},{30,30,30}}") (1,"{{40,40,40},{40,40,40},{40,40,40}}") (1,"{{50,50,50},{50,50,50},{50,50,50}}") (1,"{{60,60,60},{60,60,60},{60,60,60}}") (1,"{{70,70,70},{70,70,70},{70,70,70}}") (1,"{{80,80,80},{80,80,80},{80,80,80}}") (1,"{{90,90,90},{90,90,90},{90,90,90}}") (9 rows) , ST_Retile Return a set of configured tiles from an arbitrarily tiled raster coverage. SETOF raster ST_Retile regclass tab name col geometry ext float8 sfx float8 sfy int tw int th text algo='NearestNeighbor' Return a set of tiles having the specified scale (sfx, sfy) and max size (tw, th) and covering the specified extent (ext) with data coming from the specified raster coverage (tab, col). Algorithm options are: 'NearestNeighbor', 'Bilinear', 'Cubic', 'CubicSpline', and 'Lanczos'. Refer to: GDAL Warp resampling methods for more details. Availability: 2.2.0 ST_FromGDALRaster Returns a raster from a supported GDAL raster file. raster ST_FromGDALRaster bytea gdaldata integer srid=NULL Returns a raster from a supported GDAL raster file. gdaldata is of type bytea and should be the contents of the GDAL raster file. If srid is NULL, the function will try to autmatically assign the SRID from the GDAL raster. If srid is provided, the value provided will override any automatically assigned SRID. Availability: 2.1.0 WITH foo AS ( SELECT ST_AsPNG(ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 0.1, -0.1, 0, 0, 4326), 1, '8BUI', 1, 0), 2, '8BUI', 2, 0), 3, '8BUI', 3, 0)) AS png ), bar AS ( SELECT 1 AS rid, ST_FromGDALRaster(png) AS rast FROM foo UNION ALL SELECT 2 AS rid, ST_FromGDALRaster(png, 3310) AS rast FROM foo ) SELECT rid, ST_Metadata(rast) AS metadata, ST_SummaryStats(rast, 1) AS stats1, ST_SummaryStats(rast, 2) AS stats2, ST_SummaryStats(rast, 3) AS stats3 FROM bar ORDER BY rid; rid | metadata | stats1 | stats2 | stats3 -----+---------------------------+---------------+---------------+---------------- 1 | (0,0,2,2,1,-1,0,0,0,3) | (4,4,1,0,1,1) | (4,8,2,0,2,2) | (4,12,3,0,3,3) 2 | (0,0,2,2,1,-1,0,0,3310,3) | (4,4,1,0,1,1) | (4,8,2,0,2,2) | (4,12,3,0,3,3) (2 rows) ST_GeoReference Returns the georeference meta data in GDAL or ESRI format as commonly seen in a world file. Default is GDAL. text ST_GeoReference raster rast text format=GDAL Returns the georeference meta data including carriage return in GDAL or ESRI format as commonly seen in a world file. Default is GDAL if no type specified. type is string 'GDAL' or 'ESRI'. Difference between format representations is as follows: GDAL: scalex skewy skewx scaley upperleftx upperlefty ESRI: scalex skewy skewx scaley upperleftx + scalex*0.5 upperlefty + scaley*0.5 SELECT ST_GeoReference(rast, 'ESRI') As esri_ref, ST_GeoReference(rast, 'GDAL') As gdal_ref FROM dummy_rast WHERE rid=1; esri_ref | gdal_ref --------------+-------------- 2.0000000000 | 2.0000000000 0.0000000000 : 0.0000000000 0.0000000000 : 0.0000000000 3.0000000000 : 3.0000000000 1.5000000000 : 0.5000000000 2.0000000000 : 0.5000000000 , , ST_Height Returns the height of the raster in pixels. integer ST_Height raster rast Returns the height of the raster. SELECT rid, ST_Height(rast) As rastheight FROM dummy_rast; rid | rastheight -----+------------ 1 | 20 2 | 5 ST_IsEmpty Returns true if the raster is empty (width = 0 and height = 0). Otherwise, returns false. boolean ST_IsEmpty raster rast Returns true if the raster is empty (width = 0 and height = 0). Otherwise, returns false. Availability: 2.0.0 SELECT ST_IsEmpty(ST_MakeEmptyRaster(100, 100, 0, 0, 0, 0, 0, 0)) st_isempty | -----------+ f | SELECT ST_IsEmpty(ST_MakeEmptyRaster(0, 0, 0, 0, 0, 0, 0, 0)) st_isempty | -----------+ t | ST_MemSize Returns the amount of space (in bytes) the raster takes. integer ST_MemSize raster rast Returns the amount of space (in bytes) the raster takes. This is a nice compliment to PostgreSQL built in functions pg_column_size, pg_size_pretty, pg_relation_size, pg_total_relation_size. pg_relation_size which gives the byte size of a table may return byte size lower than ST_MemSize. This is because pg_relation_size does not add toasted table contribution and large geometries are stored in TOAST tables. pg_column_size might return lower because it returns the compressed size. pg_total_relation_size - includes, the table, the toasted tables, and the indexes. Availability: 2.2.0 SELECT ST_MemSize(ST_AsRaster(ST_Buffer(ST_Point(1,5),10,1000),150, 150, '8BUI')) As rast_mem; rast_mem -------- 22568 ST_MetaData Returns basic meta data about a raster object such as pixel size, rotation (skew), upper, lower left, etc. record ST_MetaData raster rast Returns basic meta data about a raster object such as pixel size, rotation (skew), upper, lower left, etc. Columns returned: upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands SELECT rid, (foo.md).* FROM (SELECT rid, ST_MetaData(rast) As md FROM dummy_rast) As foo; rid | upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands ----+------------+------------+-------+--------+--------+-----------+-------+-------+------+------- 1 | 0.5 | 0.5 | 10 | 20 | 2 | 3 | 0 | 0 | 0 | 0 2 | 3427927.75 | 5793244 | 5 | 5 | 0.05 | -0.05 | 0 | 0 | 0 | 3 , ST_NumBands Returns the number of bands in the raster object. integer ST_NumBands raster rast Returns the number of bands in the raster object. SELECT rid, ST_NumBands(rast) As numbands FROM dummy_rast; rid | numbands ----+---------- 1 | 0 2 | 3 ST_PixelHeight Returns the pixel height in geometric units of the spatial reference system. double precision ST_PixelHeight raster rast Returns the height of a pixel in geometric units of the spatial reference system. In the common case where there is no skew, the pixel height is just the scale ratio between geometric coordinates and raster pixels. Refer to for a diagrammatic visualization of the relationship. SELECT ST_Height(rast) As rastheight, ST_PixelHeight(rast) As pixheight, ST_ScaleX(rast) As scalex, ST_ScaleY(rast) As scaley, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy FROM dummy_rast; rastheight | pixheight | scalex | scaley | skewx | skewy ------------+-----------+--------+--------+-------+---------- 20 | 3 | 2 | 3 | 0 | 0 5 | 0.05 | 0.05 | -0.05 | 0 | 0 SELECT ST_Height(rast) As rastheight, ST_PixelHeight(rast) As pixheight, ST_ScaleX(rast) As scalex, ST_ScaleY(rast) As scaley, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy FROM (SELECT ST_SetSKew(rast,0.5,0.5) As rast FROM dummy_rast) As skewed; rastheight | pixheight | scalex | scaley | skewx | skewy -----------+-------------------+--------+--------+-------+---------- 20 | 3.04138126514911 | 2 | 3 | 0.5 | 0.5 5 | 0.502493781056044 | 0.05 | -0.05 | 0.5 | 0.5 , , , , ST_PixelWidth Returns the pixel width in geometric units of the spatial reference system. double precision ST_PixelWidth raster rast Returns the width of a pixel in geometric units of the spatial reference system. In the common case where there is no skew, the pixel width is just the scale ratio between geometric coordinates and raster pixels. The following diagram demonstrates the relationship: Pixel Width: Pixel size in the i directionPixel Height: Pixel size in the j direction SELECT ST_Width(rast) As rastwidth, ST_PixelWidth(rast) As pixwidth, ST_ScaleX(rast) As scalex, ST_ScaleY(rast) As scaley, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy FROM dummy_rast; rastwidth | pixwidth | scalex | scaley | skewx | skewy -----------+----------+--------+--------+-------+---------- 10 | 2 | 2 | 3 | 0 | 0 5 | 0.05 | 0.05 | -0.05 | 0 | 0 SELECT ST_Width(rast) As rastwidth, ST_PixelWidth(rast) As pixwidth, ST_ScaleX(rast) As scalex, ST_ScaleY(rast) As scaley, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy FROM (SELECT ST_SetSkew(rast,0.5,0.5) As rast FROM dummy_rast) As skewed; rastwidth | pixwidth | scalex | scaley | skewx | skewy -----------+-------------------+--------+--------+-------+---------- 10 | 2.06155281280883 | 2 | 3 | 0.5 | 0.5 5 | 0.502493781056044 | 0.05 | -0.05 | 0.5 | 0.5 , , , , ST_ScaleX Returns the X component of the pixel width in units of coordinate reference system. float8 ST_ScaleX raster rast Returns the X component of the pixel width in units of coordinate reference system. Refer to World File for more details. Changed: 2.0.0. In WKTRaster versions this was called ST_PixelSizeX. SELECT rid, ST_ScaleX(rast) As rastpixwidth FROM dummy_rast; rid | rastpixwidth -----+-------------- 1 | 2 2 | 0.05 ST_ScaleY Returns the Y component of the pixel height in units of coordinate reference system. float8 ST_ScaleY raster rast Returns the Y component of the pixel height in units of coordinate reference system. May be negative. Refer to World File for more details. Changed: 2.0.0. In WKTRaster versions this was called ST_PixelSizeY. SELECT rid, ST_ScaleY(rast) As rastpixheight FROM dummy_rast; rid | rastpixheight -----+--------------- 1 | 3 2 | -0.05 ST_RasterToWorldCoord Returns the raster's upper left corner as geometric X and Y (longitude and latitude) given a column and row. Column and row starts at 1. record ST_RasterToWorldCoord raster rast integer xcolumn integer yrow Returns the upper left corner as geometric X and Y (longitude and latitude) given a column and row. Returned X and Y are in geometric units of the georeferenced raster. Numbering of column and row starts at 1 but if either parameter is passed a zero, a negative number or a number greater than the respective dimension of the raster, it will return coordinates outside of the raster assuming the raster's grid is applicable outside the raster's bounds. Availability: 2.1.0 -- non-skewed raster SELECT rid, (ST_RasterToWorldCoord(rast,1, 1)).*, (ST_RasterToWorldCoord(rast,2, 2)).* FROM dummy_rast rid | longitude | latitude | longitude | latitude -----+------------+----------+-----------+------------ 1 | 0.5 | 0.5 | 2.5 | 3.5 2 | 3427927.75 | 5793244 | 3427927.8 | 5793243.95 -- skewed raster SELECT rid, (ST_RasterToWorldCoord(rast, 1, 1)).*, (ST_RasterToWorldCoord(rast, 2, 3)).* FROM ( SELECT rid, ST_SetSkew(rast, 100.5, 0) As rast FROM dummy_rast ) As foo rid | longitude | latitude | longitude | latitude -----+------------+----------+-----------+----------- 1 | 0.5 | 0.5 | 203.5 | 6.5 2 | 3427927.75 | 5793244 | 3428128.8 | 5793243.9 , , ST_RasterToWorldCoordX Returns the geometric X coordinate upper left of a raster, column and row. Numbering of columns and rows starts at 1. float8 ST_RasterToWorldCoordX raster rast integer xcolumn float8 ST_RasterToWorldCoordX raster rast integer xcolumn integer yrow Returns the upper left X coordinate of a raster column row in geometric units of the georeferenced raster. Numbering of columns and rows starts at 1 but if you pass in a negative number or number higher than number of columns in raster, it will give you coordinates outside of the raster file to left or right with the assumption that the skew and pixel sizes are same as selected raster. For non-skewed rasters, providing the X column is sufficient. For skewed rasters, the georeferenced coordinate is a function of the ST_ScaleX and ST_SkewX and row and column. An error will be raised if you give just the X column for a skewed raster. Changed: 2.1.0 In prior versions, this was called ST_Raster2WorldCoordX -- non-skewed raster providing column is sufficient SELECT rid, ST_RasterToWorldCoordX(rast,1) As x1coord, ST_RasterToWorldCoordX(rast,2) As x2coord, ST_ScaleX(rast) As pixelx FROM dummy_rast; rid | x1coord | x2coord | pixelx -----+------------+-----------+-------- 1 | 0.5 | 2.5 | 2 2 | 3427927.75 | 3427927.8 | 0.05 -- for fun lets skew it SELECT rid, ST_RasterToWorldCoordX(rast, 1, 1) As x1coord, ST_RasterToWorldCoordX(rast, 2, 3) As x2coord, ST_ScaleX(rast) As pixelx FROM (SELECT rid, ST_SetSkew(rast, 100.5, 0) As rast FROM dummy_rast) As foo; rid | x1coord | x2coord | pixelx -----+------------+-----------+-------- 1 | 0.5 | 203.5 | 2 2 | 3427927.75 | 3428128.8 | 0.05 , , , ST_RasterToWorldCoordY Returns the geometric Y coordinate upper left corner of a raster, column and row. Numbering of columns and rows starts at 1. float8 ST_RasterToWorldCoordY raster rast integer yrow float8 ST_RasterToWorldCoordY raster rast integer xcolumn integer yrow Returns the upper left Y coordinate of a raster column row in geometric units of the georeferenced raster. Numbering of columns and rows starts at 1 but if you pass in a negative number or number higher than number of columns/rows in raster, it will give you coordinates outside of the raster file to left or right with the assumption that the skew and pixel sizes are same as selected raster tile. For non-skewed rasters, providing the Y column is sufficient. For skewed rasters, the georeferenced coordinate is a function of the ST_ScaleY and ST_SkewY and row and column. An error will be raised if you give just the Y row for a skewed raster. Changed: 2.1.0 In prior versions, this was called ST_Raster2WorldCoordY -- non-skewed raster providing row is sufficient SELECT rid, ST_RasterToWorldCoordY(rast,1) As y1coord, ST_RasterToWorldCoordY(rast,3) As y2coord, ST_ScaleY(rast) As pixely FROM dummy_rast; rid | y1coord | y2coord | pixely -----+---------+-----------+-------- 1 | 0.5 | 6.5 | 3 2 | 5793244 | 5793243.9 | -0.05 -- for fun lets skew it SELECT rid, ST_RasterToWorldCoordY(rast,1,1) As y1coord, ST_RasterToWorldCoordY(rast,2,3) As y2coord, ST_ScaleY(rast) As pixely FROM (SELECT rid, ST_SetSkew(rast,0,100.5) As rast FROM dummy_rast) As foo; rid | y1coord | y2coord | pixely -----+---------+-----------+-------- 1 | 0.5 | 107 | 3 2 | 5793244 | 5793344.4 | -0.05 , , , ST_Rotation Returns the rotation of the raster in radian. float8 ST_Rotation raster rast Returns the uniform rotation of the raster in radian. If a raster does not have uniform rotation, NaN is returned. Refer to World File for more details. SELECT rid, ST_Rotation(ST_SetScale(ST_SetSkew(rast, sqrt(2)), sqrt(2))) as rot FROM dummy_rast; rid | rot -----+------------------- 1 | 0.785398163397448 2 | 0.785398163397448 , , ST_SkewX Returns the georeference X skew (or rotation parameter). float8 ST_SkewX raster rast Returns the georeference X skew (or rotation parameter). Refer to World File for more details. SELECT rid, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy, ST_GeoReference(rast) as georef FROM dummy_rast; rid | skewx | skewy | georef -----+-------+-------+-------------------- 1 | 0 | 0 | 2.0000000000 : 0.0000000000 : 0.0000000000 : 3.0000000000 : 0.5000000000 : 0.5000000000 : 2 | 0 | 0 | 0.0500000000 : 0.0000000000 : 0.0000000000 : -0.0500000000 : 3427927.7500000000 : 5793244.0000000000 , , ST_SkewY Returns the georeference Y skew (or rotation parameter). float8 ST_SkewY raster rast Returns the georeference Y skew (or rotation parameter). Refer to World File for more details. SELECT rid, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy, ST_GeoReference(rast) as georef FROM dummy_rast; rid | skewx | skewy | georef -----+-------+-------+-------------------- 1 | 0 | 0 | 2.0000000000 : 0.0000000000 : 0.0000000000 : 3.0000000000 : 0.5000000000 : 0.5000000000 : 2 | 0 | 0 | 0.0500000000 : 0.0000000000 : 0.0000000000 : -0.0500000000 : 3427927.7500000000 : 5793244.0000000000 , , ST_SRID Returns the spatial reference identifier of the raster as defined in spatial_ref_sys table. integer ST_SRID raster rast Returns the spatial reference identifier of the raster object as defined in the spatial_ref_sys table. From PostGIS 2.0+ the srid of a non-georeferenced raster/geometry is 0 instead of the prior -1. SELECT ST_SRID(rast) As srid FROM dummy_rast WHERE rid=1; srid ---------------- 0 , ST_Summary Returns a text summary of the contents of the raster. text ST_Summary raster rast Returns a text summary of the contents of the raster. Availability: 2.1.0 SELECT ST_Summary( ST_AddBand( ST_AddBand( ST_AddBand( ST_MakeEmptyRaster(10, 10, 0, 0, 1, -1, 0, 0, 0) , 1, '8BUI', 1, 0 ) , 2, '32BF', 0, -9999 ) , 3, '16BSI', 0, NULL ) ); st_summary ------------------------------------------------------------------ Raster of 10x10 pixels has 3 bands and extent of BOX(0 -10,10 0)+ band 1 of pixtype 8BUI is in-db with NODATA value of 0 + band 2 of pixtype 32BF is in-db with NODATA value of -9999 + band 3 of pixtype 16BSI is in-db with no NODATA value (1 row) , , ST_UpperLeftX Returns the upper left X coordinate of raster in projected spatial ref. float8 ST_UpperLeftX raster rast Returns the upper left X coordinate of raster in projected spatial ref. SELECt rid, ST_UpperLeftX(rast) As ulx FROM dummy_rast; rid | ulx -----+------------ 1 | 0.5 2 | 3427927.75 , , ST_UpperLeftY Returns the upper left Y coordinate of raster in projected spatial ref. float8 ST_UpperLeftY raster rast Returns the upper left Y coordinate of raster in projected spatial ref. SELECT rid, ST_UpperLeftY(rast) As uly FROM dummy_rast; rid | uly -----+--------- 1 | 0.5 2 | 5793244 , , ST_Width Returns the width of the raster in pixels. integer ST_Width raster rast Returns the width of the raster in pixels. SELECT ST_Width(rast) As rastwidth FROM dummy_rast WHERE rid=1; rastwidth ---------------- 10 ST_WorldToRasterCoord Returns the upper left corner as column and row given geometric X and Y (longitude and latitude) or a point geometry expressed in the spatial reference coordinate system of the raster. record ST_WorldToRasterCoord raster rast geometry pt record ST_WorldToRasterCoord raster rast double precision longitude double precision latitude Returns the upper left corner as column and row given geometric X and Y (longitude and latitude) or a point geometry. This function works regardless of whether or not the geometric X and Y or point geometry is outside the extent of the raster. Geometric X and Y must be expressed in the spatial reference coordinate system of the raster. Availability: 2.1.0 SELECT rid, (ST_WorldToRasterCoord(rast,3427927.8,20.5)).*, (ST_WorldToRasterCoord(rast,ST_GeomFromText('POINT(3427927.8 20.5)',ST_SRID(rast)))).* FROM dummy_rast; rid | columnx | rowy | columnx | rowy -----+---------+-----------+---------+----------- 1 | 1713964 | 7 | 1713964 | 7 2 | 2 | 115864471 | 2 | 115864471 , , , , ST_WorldToRasterCoordX Returns the column in the raster of the point geometry (pt) or a X and Y world coordinate (xw, yw) represented in world spatial reference system of raster. integer ST_WorldToRasterCoordX raster rast geometry pt integer ST_WorldToRasterCoordX raster rast double precision xw integer ST_WorldToRasterCoordX raster rast double precision xw double precision yw Returns the column in the raster of the point geometry (pt) or a X and Y world coordinate (xw, yw). A point, or (both xw and yw world coordinates are required if a raster is skewed). If a raster is not skewed then xw is sufficient. World coordinates are in the spatial reference coordinate system of the raster. Changed: 2.1.0 In prior versions, this was called ST_World2RasterCoordX SELECT rid, ST_WorldToRasterCoordX(rast,3427927.8) As xcoord, ST_WorldToRasterCoordX(rast,3427927.8,20.5) As xcoord_xwyw, ST_WorldToRasterCoordX(rast,ST_GeomFromText('POINT(3427927.8 20.5)',ST_SRID(rast))) As ptxcoord FROM dummy_rast; rid | xcoord | xcoord_xwyw | ptxcoord -----+---------+---------+---------- 1 | 1713964 | 1713964 | 1713964 2 | 1 | 1 | 1 , , ST_WorldToRasterCoordY Returns the row in the raster of the point geometry (pt) or a X and Y world coordinate (xw, yw) represented in world spatial reference system of raster. integer ST_WorldToRasterCoordY raster rast geometry pt integer ST_WorldToRasterCoordY raster rast double precision xw integer ST_WorldToRasterCoordY raster rast double precision xw double precision yw Returns the row in the raster of the point geometry (pt) or a X and Y world coordinate (xw, yw). A point, or (both xw and yw world coordinates are required if a raster is skewed). If a raster is not skewed then xw is sufficient. World coordinates are in the spatial reference coordinate system of the raster. Changed: 2.1.0 In prior versions, this was called ST_World2RasterCoordY SELECT rid, ST_WorldToRasterCoordY(rast,20.5) As ycoord, ST_WorldToRasterCoordY(rast,3427927.8,20.5) As ycoord_xwyw, ST_WorldToRasterCoordY(rast,ST_GeomFromText('POINT(3427927.8 20.5)',ST_SRID(rast))) As ptycoord FROM dummy_rast; rid | ycoord | ycoord_xwyw | ptycoord -----+-----------+-------------+----------- 1 | 7 | 7 | 7 2 | 115864471 | 115864471 | 115864471 , , ST_BandMetaData Returns basic meta data for a specific raster band. band num 1 is assumed if none-specified. record ST_BandMetaData raster rast integer bandnum=1 Returns basic meta data about a raster band. Columns returned pixeltype | nodatavalue | isoutdb | path. If raster contains no bands then an error is thrown. If band has no NODATA value, nodatavalue will be NULL. SELECT rid, (foo.md).* FROM (SELECT rid, ST_BandMetaData(rast,1) As md FROM dummy_rast WHERE rid=2) As foo; rid | pixeltype | nodatavalue | isoutdb | path -----+-----------+----------------+-------------+---------+------ 2 | 8BUI | 0 | f | , ST_BandNoDataValue Returns the value in a given band that represents no data. If no band num 1 is assumed. double precision ST_BandNoDataValue raster rast integer bandnum=1 Returns the value that represents no data for the band SELECT ST_BandNoDataValue(rast,1) As bnval1, ST_BandNoDataValue(rast,2) As bnval2, ST_BandNoDataValue(rast,3) As bnval3 FROM dummy_rast WHERE rid = 2; bnval1 | bnval2 | bnval3 --------+--------+-------- 0 | 0 | 0 ST_BandIsNoData Returns true if the band is filled with only nodata values. boolean ST_BandIsNoData raster rast integer band boolean forceChecking=true boolean ST_BandIsNoData raster rast boolean forceChecking=true Returns true if the band is filled with only nodata values. Band 1 is assumed if not specified. If the last argument is TRUE, the entire band is checked pixel by pixel. Otherwise, the function simply returns the value of the isnodata flag for the band. The default value for this parameter is FALSE, if not specified. Availability: 2.0.0 If the flag is dirty (this is, the result is different using TRUE as last parameter and not using it) you should update the raster to set this flag to true, by using ST_SetBandIsNodata(), or ST_SetBandNodataValue() with TRUE as last argument. See . -- Create dummy table with one raster column create table dummy_rast (rid integer, rast raster); -- Add raster with two bands, one pixel/band. In the first band, nodatavalue = pixel value = 3. -- In the second band, nodatavalue = 13, pixel value = 4 insert into dummy_rast values(1, ( '01' -- little endian (uint8 ndr) || '0000' -- version (uint16 0) || '0200' -- nBands (uint16 0) || '17263529ED684A3F' -- scaleX (float64 0.000805965234044584) || 'F9253529ED684ABF' -- scaleY (float64 -0.00080596523404458) || '1C9F33CE69E352C0' -- ipX (float64 -75.5533328537098) || '718F0E9A27A44840' -- ipY (float64 49.2824585505576) || 'ED50EB853EC32B3F' -- skewX (float64 0.000211812383858707) || '7550EB853EC32B3F' -- skewY (float64 0.000211812383858704) || 'E6100000' -- SRID (int32 4326) || '0100' -- width (uint16 1) || '0100' -- height (uint16 1) || '6' -- hasnodatavalue and isnodata value set to true. || '2' -- first band type (4BUI) || '03' -- novalue==3 || '03' -- pixel(0,0)==3 (same that nodata) || '0' -- hasnodatavalue set to false || '5' -- second band type (16BSI) || '0D00' -- novalue==13 || '0400' -- pixel(0,0)==4 )::raster ); select st_bandisnodata(rast, 1) from dummy_rast where rid = 1; -- Expected true select st_bandisnodata(rast, 2) from dummy_rast where rid = 1; -- Expected false , , , ST_BandPath Returns system file path to a band stored in file system. If no bandnum specified, 1 is assumed. text ST_BandPath raster rast integer bandnum=1 Returns system file path to a band. Throws an error if called with an in db band. ST_BandPixelType Returns the type of pixel for given band. If no bandnum specified, 1 is assumed. text ST_BandPixelType raster rast integer bandnum=1 Returns the value that represents no data for the band There are 11 pixel types. Pixel Types supported are as follows: 1BB - 1-bit boolean 2BUI - 2-bit unsigned integer 4BUI - 4-bit unsigned integer 8BSI - 8-bit signed integer 8BUI - 8-bit unsigned integer 16BSI - 16-bit signed integer 16BUI - 16-bit unsigned integer 32BSI - 32-bit signed integer 32BUI - 32-bit unsigned integer 32BF - 32-bit float 64BF - 64-bit float SELECT ST_BandPixelType(rast,1) As btype1, ST_BandPixelType(rast,2) As btype2, ST_BandPixelType(rast,3) As btype3 FROM dummy_rast WHERE rid = 2; btype1 | btype2 | btype3 --------+--------+-------- 8BUI | 8BUI | 8BUI ST_HasNoBand Returns true if there is no band with given band number. If no band number is specified, then band number 1 is assumed. boolean ST_HasNoBand raster rast integer bandnum=1 Returns true if there is no band with given band number. If no band number is specified, then band number 1 is assumed. Availability: 2.0.0 SELECT rid, ST_HasNoBand(rast) As hb1, ST_HasNoBand(rast,2) as hb2, ST_HasNoBand(rast,4) as hb4, ST_NumBands(rast) As numbands FROM dummy_rast; rid | hb1 | hb2 | hb4 | numbands -----+-----+-----+-----+---------- 1 | t | t | t | 0 2 | f | f | t | 3 ST_PixelAsPolygon Returns the polygon geometry that bounds the pixel for a particular row and column. geometry ST_PixelAsPolygon raster rast integer columnx integer rowy Returns the polygon geometry that bounds the pixel for a particular row and column. Availability: 2.0.0 -- get raster pixel polygon SELECT i,j, ST_AsText(ST_PixelAsPolygon(foo.rast, i,j)) As b1pgeom FROM dummy_rast As foo CROSS JOIN generate_series(1,2) As i CROSS JOIN generate_series(1,1) As j WHERE rid=2; i | j | b1pgeom ---+---+----------------------------------------------------------------------------- 1 | 1 | POLYGON((3427927.75 5793244,3427927.8 5793244,3427927.8 5793243.95,... 2 | 1 | POLYGON((3427927.8 5793244,3427927.85 5793244,3427927.85 5793243.95, .. , , , , , , , ST_PixelAsPolygons Returns the polygon geometry that bounds every pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. setof record ST_PixelAsPolygons raster rast integer band=1 boolean exclude_nodata_value=TRUE Returns the polygon geometry that bounds every pixel of a raster band along with the value (double precision), the X and the Y raster coordinates (integers) of each pixel. ST_PixelAsPolygons returns one polygon geometry for every pixel. This is different than ST_DumpAsPolygons where each geometry represents one or more pixels with the same pixel value. When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as polygons. Availability: 2.0.0 Enhanced: 2.1.0 exclude_nodata_value optional argument was added. Changed: 2.1.1 Changed behavior of exclude_nodata_value. -- get raster pixel polygon SELECT (gv).x, (gv).y, (gv).val, ST_AsText((gv).geom) geom FROM (SELECT ST_PixelAsPolygons( ST_SetValue(ST_SetValue(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 0.001, -0.001, 0.001, 0.001, 4269), '8BUI'::text, 1, 0), 2, 2, 10), 1, 1, NULL) ) gv ) foo; x | y | val | geom ---+---+----------------------------------------------------------------------------- 1 | 1 | | POLYGON((0 0,0.001 0.001,0.002 0,0.001 -0.001,0 0)) 1 | 2 | 1 | POLYGON((0.001 -0.001,0.002 0,0.003 -0.001,0.002 -0.002,0.001 -0.001)) 2 | 1 | 1 | POLYGON((0.001 0.001,0.002 0.002,0.003 0.001,0.002 0,0.001 0.001)) 2 | 2 | 10 | POLYGON((0.002 0,0.003 0.001,0.004 0,0.003 -0.001,0.002 0)) , , , , , , ST_PixelAsPoint Returns a point geometry of the pixel's upper-left corner. geometry ST_PixelAsPoint raster rast integer columnx integer rowy Returns a point geometry of the pixel's upper-left corner. Availability: 2.1.0 SELECT ST_AsText(ST_PixelAsPoint(rast, 1, 1)) FROM dummy_rast WHERE rid = 1; st_astext ---------------- POINT(0.5 0.5) , , , , , ST_PixelAsPoints Returns a point geometry for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The coordinates of the point geometry are of the pixel's upper-left corner. geometry ST_PixelAsPoints raster rast integer band=1 boolean exclude_nodata_value=TRUE Returns a point geometry for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The coordinates of the point geometry are of the pixel's upper-left corner. When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as points. Availability: 2.1.0 Changed: 2.1.1 Changed behavior of exclude_nodata_value. SELECT x, y, val, ST_AsText(geom) FROM (SELECT (ST_PixelAsPoints(rast, 1)).* FROM dummy_rast WHERE rid = 2) foo; x | y | val | st_astext ---+---+-----+------------------------------ 1 | 1 | 253 | POINT(3427927.75 5793244) 2 | 1 | 254 | POINT(3427927.8 5793244) 3 | 1 | 253 | POINT(3427927.85 5793244) 4 | 1 | 254 | POINT(3427927.9 5793244) 5 | 1 | 254 | POINT(3427927.95 5793244) 1 | 2 | 253 | POINT(3427927.75 5793243.95) 2 | 2 | 254 | POINT(3427927.8 5793243.95) 3 | 2 | 254 | POINT(3427927.85 5793243.95) 4 | 2 | 253 | POINT(3427927.9 5793243.95) 5 | 2 | 249 | POINT(3427927.95 5793243.95) 1 | 3 | 250 | POINT(3427927.75 5793243.9) 2 | 3 | 254 | POINT(3427927.8 5793243.9) 3 | 3 | 254 | POINT(3427927.85 5793243.9) 4 | 3 | 252 | POINT(3427927.9 5793243.9) 5 | 3 | 249 | POINT(3427927.95 5793243.9) 1 | 4 | 251 | POINT(3427927.75 5793243.85) 2 | 4 | 253 | POINT(3427927.8 5793243.85) 3 | 4 | 254 | POINT(3427927.85 5793243.85) 4 | 4 | 254 | POINT(3427927.9 5793243.85) 5 | 4 | 253 | POINT(3427927.95 5793243.85) 1 | 5 | 252 | POINT(3427927.75 5793243.8) 2 | 5 | 250 | POINT(3427927.8 5793243.8) 3 | 5 | 254 | POINT(3427927.85 5793243.8) 4 | 5 | 254 | POINT(3427927.9 5793243.8) 5 | 5 | 254 | POINT(3427927.95 5793243.8) , , , , , ST_PixelAsCentroid Returns the centroid (point geometry) of the area represented by a pixel. geometry ST_PixelAsCentroid raster rast integer columnx integer rowy Returns the centroid (point geometry) of the area represented by a pixel. Availability: 2.1.0 SELECT ST_AsText(ST_PixelAsCentroid(rast, 1, 1)) FROM dummy_rast WHERE rid = 1; st_astext -------------- POINT(1.5 2) , , , , , ST_PixelAsCentroids Returns the centroid (point geometry) for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The point geometry is the centroid of the area represented by a pixel. geometry ST_PixelAsCentroids raster rast integer band=1 boolean exclude_nodata_value=TRUE Returns the centroid (point geometry) for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The point geometry is the centroid of the area represented by a pixel. When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as points. Availability: 2.1.0 Changed: 2.1.1 Changed behavior of exclude_nodata_value. SELECT x, y, val, ST_AsText(geom) FROM (SELECT (ST_PixelAsCentroids(rast, 1)).* FROM dummy_rast WHERE rid = 2) foo; x | y | val | st_astext ---+---+-----+-------------------------------- 1 | 1 | 253 | POINT(3427927.775 5793243.975) 2 | 1 | 254 | POINT(3427927.825 5793243.975) 3 | 1 | 253 | POINT(3427927.875 5793243.975) 4 | 1 | 254 | POINT(3427927.925 5793243.975) 5 | 1 | 254 | POINT(3427927.975 5793243.975) 1 | 2 | 253 | POINT(3427927.775 5793243.925) 2 | 2 | 254 | POINT(3427927.825 5793243.925) 3 | 2 | 254 | POINT(3427927.875 5793243.925) 4 | 2 | 253 | POINT(3427927.925 5793243.925) 5 | 2 | 249 | POINT(3427927.975 5793243.925) 1 | 3 | 250 | POINT(3427927.775 5793243.875) 2 | 3 | 254 | POINT(3427927.825 5793243.875) 3 | 3 | 254 | POINT(3427927.875 5793243.875) 4 | 3 | 252 | POINT(3427927.925 5793243.875) 5 | 3 | 249 | POINT(3427927.975 5793243.875) 1 | 4 | 251 | POINT(3427927.775 5793243.825) 2 | 4 | 253 | POINT(3427927.825 5793243.825) 3 | 4 | 254 | POINT(3427927.875 5793243.825) 4 | 4 | 254 | POINT(3427927.925 5793243.825) 5 | 4 | 253 | POINT(3427927.975 5793243.825) 1 | 5 | 252 | POINT(3427927.775 5793243.775) 2 | 5 | 250 | POINT(3427927.825 5793243.775) 3 | 5 | 254 | POINT(3427927.875 5793243.775) 4 | 5 | 254 | POINT(3427927.925 5793243.775) 5 | 5 | 254 | POINT(3427927.975 5793243.775) , , , , , ST_Value Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster. double precision ST_Value raster rast geometry pt boolean exclude_nodata_value=true double precision ST_Value raster rast integer bandnum geometry pt boolean exclude_nodata_value=true double precision ST_Value raster rast integer columnx integer rowy boolean exclude_nodata_value=true double precision ST_Value raster rast integer bandnum integer columnx integer rowy boolean exclude_nodata_value=true Returns the value of a given band in a given columnx, rowy pixel or at a given geometry point. Band numbers start at 1 and band is assumed to be 1 if not specified. If exclude_nodata_value is set to true, then only non nodata pixels are considered. If exclude_nodata_value is set to false, then all pixels are considered. Enhanced: 2.0.0 exclude_nodata_value optional argument was added. -- get raster values at particular postgis geometry points -- the srid of your geometry should be same as for your raster SELECT rid, ST_Value(rast, foo.pt_geom) As b1pval, ST_Value(rast, 2, foo.pt_geom) As b2pval FROM dummy_rast CROSS JOIN (SELECT ST_SetSRID(ST_Point(3427927.77, 5793243.76), 0) As pt_geom) As foo WHERE rid=2; rid | b1pval | b2pval -----+--------+-------- 2 | 252 | 79 -- general fictitious example using a real table SELECT rid, ST_Value(rast, 3, sometable.geom) As b3pval FROM sometable WHERE ST_Intersects(rast,sometable.geom); SELECT rid, ST_Value(rast, 1, 1, 1) As b1pval, ST_Value(rast, 2, 1, 1) As b2pval, ST_Value(rast, 3, 1, 1) As b3pval FROM dummy_rast WHERE rid=2; rid | b1pval | b2pval | b3pval -----+--------+--------+-------- 2 | 253 | 78 | 70 --- Get all values in bands 1,2,3 of each pixel -- SELECT x, y, ST_Value(rast, 1, x, y) As b1val, ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val FROM dummy_rast CROSS JOIN generate_series(1, 1000) As x CROSS JOIN generate_series(1, 1000) As y WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast); x | y | b1val | b2val | b3val ---+---+-------+-------+------- 1 | 1 | 253 | 78 | 70 1 | 2 | 253 | 96 | 80 1 | 3 | 250 | 99 | 90 1 | 4 | 251 | 89 | 77 1 | 5 | 252 | 79 | 62 2 | 1 | 254 | 98 | 86 2 | 2 | 254 | 118 | 108 : : --- Get all values in bands 1,2,3 of each pixel same as above but returning the upper left point point of each pixel -- SELECT ST_AsText(ST_SetSRID( ST_Point(ST_UpperLeftX(rast) + ST_ScaleX(rast)*x, ST_UpperLeftY(rast) + ST_ScaleY(rast)*y), ST_SRID(rast))) As uplpt , ST_Value(rast, 1, x, y) As b1val, ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val FROM dummy_rast CROSS JOIN generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast); uplpt | b1val | b2val | b3val -----------------------------+-------+-------+------- POINT(3427929.25 5793245.5) | 253 | 78 | 70 POINT(3427929.25 5793247) | 253 | 96 | 80 POINT(3427929.25 5793248.5) | 250 | 99 | 90 : --- Get a polygon formed by union of all pixels that fall in a particular value range and intersect particular polygon -- SELECT ST_AsText(ST_Union(pixpolyg)) As shadow FROM (SELECT ST_Translate(ST_MakeEnvelope( ST_UpperLeftX(rast), ST_UpperLeftY(rast), ST_UpperLeftX(rast) + ST_ScaleX(rast), ST_UpperLeftY(rast) + ST_ScaleY(rast), 0 ), ST_ScaleX(rast)*x, ST_ScaleY(rast)*y ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val FROM dummy_rast CROSS JOIN generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast)) As foo WHERE ST_Intersects( pixpolyg, ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0) ) AND b2val != 254; shadow ------------------------------------------------------------------------------------ MULTIPOLYGON(((3427928 5793243.9,3427928 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9, 3427927.95 5793243.95,3427928 5793243.95,3427928.05 5793243.95,3427928.05 5793243.9,3427928 5793243.9)),((3427927.95 5793243.9,3427927.95 579324 3.85,3427927.9 5793243.85,3427927.85 5793243.85,3427927.85 5793243.9,3427927.9 5793243.9,3427927.9 5793243.95, 3427927.95 5793243.95,3427927.95 5793243.9)),((3427927.85 5793243.75,3427927.85 5793243.7,3427927.8 5793243.7,3427927.8 5793243.75 ,3427927.8 5793243.8,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75)), ((3427928.05 5793243.75,3427928.05 5793243.7,3427928 5793243.7,3427927.95 5793243.7,3427927.95 5793243.75,3427927.95 5793243.8,3427 927.95 5793243.85,3427928 5793243.85,3427928 5793243.8,3427928.05 5793243.8, 3427928.05 5793243.75)),((3427927.95 5793243.75,3427927.95 5793243.7,3427927.9 5793243.7,3427927.85 5793243.7, 3427927.85 5793243.75,3427927.85 5793243.8,3427927.85 5793243.85,3427927.9 5793243.85, 3427927.95 5793243.85,3427927.95 5793243.8,3427927.95 5793243.75))) --- Checking all the pixels of a large raster tile can take a long time. --- You can dramatically improve speed at some lose of precision by orders of magnitude -- by sampling pixels using the step optional parameter of generate_series. -- This next example does the same as previous but by checking 1 for every 4 (2x2) pixels and putting in the last checked -- putting in the checked pixel as the value for subsequent 4 SELECT ST_AsText(ST_Union(pixpolyg)) As shadow FROM (SELECT ST_Translate(ST_MakeEnvelope( ST_UpperLeftX(rast), ST_UpperLeftY(rast), ST_UpperLeftX(rast) + ST_ScaleX(rast)*2, ST_UpperLeftY(rast) + ST_ScaleY(rast)*2, 0 ), ST_ScaleX(rast)*x, ST_ScaleY(rast)*y ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val FROM dummy_rast CROSS JOIN generate_series(1,1000,2) As x CROSS JOIN generate_series(1,1000,2) As y WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast) ) As foo WHERE ST_Intersects( pixpolyg, ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0) ) AND b2val != 254; shadow ------------------------------------------------------------------------------------ MULTIPOLYGON(((3427927.9 5793243.85,3427927.8 5793243.85,3427927.8 5793243.95, 3427927.9 5793243.95,3427928 5793243.95,3427928.1 5793243.95,3427928.1 5793243.85,3427928 5793243.85,3427927.9 5793243.85)), ((3427927.9 5793243.65,3427927.8 5793243.65,3427927.8 5793243.75,3427927.8 5793243.85,3427927.9 5793243.85, 3427928 5793243.85,3427928 5793243.75,3427928.1 5793243.75,3427928.1 5793243.65,3427928 5793243.65,3427927.9 5793243.65))) , , , , , , , , , , , , , ST_NearestValue Returns the nearest non-NODATA value of a given band's pixel specified by a columnx and rowy or a geometric point expressed in the same spatial reference coordinate system as the raster. double precision ST_NearestValue raster rast integer bandnum geometry pt boolean exclude_nodata_value=true double precision ST_NearestValue raster rast geometry pt boolean exclude_nodata_value=true double precision ST_NearestValue raster rast integer bandnum integer columnx integer rowy boolean exclude_nodata_value=true double precision ST_NearestValue raster rast integer columnx integer rowy boolean exclude_nodata_value=true Returns the nearest non-NODATA value of a given band in a given columnx, rowy pixel or at a specific geometric point. If the columnx, rowy pixel or the pixel at the specified geometric point is NODATA, the function will find the nearest pixel to the columnx, rowy pixel or geometric point whose value is not NODATA. Band numbers start at 1 and bandnum is assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster. Availability: 2.1.0 ST_NearestValue is a drop-in replacement for ST_Value. -- pixel 2x2 has value SELECT ST_Value(rast, 2, 2) AS value, ST_NearestValue(rast, 2, 2) AS nearestvalue FROM ( SELECT ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 0. ), 2, 3, 0. ), 3, 5, 0. ), 4, 2, 0. ), 5, 4, 0. ) AS rast ) AS foo value | nearestvalue -------+-------------- 1 | 1 -- pixel 2x3 is NODATA SELECT ST_Value(rast, 2, 3) AS value, ST_NearestValue(rast, 2, 3) AS nearestvalue FROM ( SELECT ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 0. ), 2, 3, 0. ), 3, 5, 0. ), 4, 2, 0. ), 5, 4, 0. ) AS rast ) AS foo value | nearestvalue -------+-------------- | 1 , ST_Neighborhood Returns a 2-D double precision array of the non-NODATA values around a given band's pixel specified by either a columnX and rowY or a geometric point expressed in the same spatial reference coordinate system as the raster. double precision[][] ST_Neighborhood raster rast integer bandnum integer columnX integer rowY integer distanceX integer distanceY boolean exclude_nodata_value=true double precision[][] ST_Neighborhood raster rast integer columnX integer rowY integer distanceX integer distanceY boolean exclude_nodata_value=true double precision[][] ST_Neighborhood raster rast integer bandnum geometry pt integer distanceX integer distanceY boolean exclude_nodata_value=true double precision[][] ST_Neighborhood raster rast geometry pt integer distanceX integer distanceY boolean exclude_nodata_value=true Returns a 2-D double precision array of the non-NODATA values around a given band's pixel specified by either a columnX and rowY or a geometric point expressed in the same spatial reference coordinate system as the raster. The distanceX and distanceY parameters define the number of pixels around the specified pixel in the X and Y axes, e.g. I want all values within 3 pixel distance along the X axis and 2 pixel distance along the Y axis around my pixel of interest. The center value of the 2-D array will be the value at the pixel specified by the columnX and rowY or the geometric point. Band numbers start at 1 and bandnum is assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster. The number of elements along each axis of the returning 2-D array is 2 * (distanceX|distanceY) + 1. So for a distanceX and distanceY of 1, the returning array will be 3x3. The 2-D array output can be passed to any of the raster processing builtin functions, e.g. ST_Min4ma, ST_Sum4ma, ST_Mean4ma. Availability: 2.1.0 -- pixel 2x2 has value SELECT ST_Neighborhood(rast, 2, 2, 1, 1) FROM ( SELECT ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 1, ARRAY[ [0, 1, 1, 1, 1], [1, 1, 1, 0, 1], [1, 0, 1, 1, 1], [1, 1, 1, 1, 0], [1, 1, 0, 1, 1] ]::double precision[], 1 ) AS rast ) AS foo st_neighborhood --------------------------------- {{NULL,1,1},{1,1,NULL},{1,1,1}} -- pixel 2x3 is NODATA SELECT ST_Neighborhood(rast, 2, 3, 1, 1) FROM ( SELECT ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 1, ARRAY[ [0, 1, 1, 1, 1], [1, 1, 1, 0, 1], [1, 0, 1, 1, 1], [1, 1, 1, 1, 0], [1, 1, 0, 1, 1] ]::double precision[], 1 ) AS rast ) AS foo st_neighborhood ------------------------------ {{1,1,1},{1,NULL,1},{1,1,1}} -- pixel 3x3 has value -- exclude_nodata_value = FALSE SELECT ST_Neighborhood(rast, 3, 3, 1, 1, false) FROM ( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 1, ARRAY[ [0, 1, 1, 1, 1], [1, 1, 1, 0, 1], [1, 0, 1, 1, 1], [1, 1, 1, 1, 0], [1, 1, 0, 1, 1] ]::double precision[], 1 ) AS rast ) AS foo st_neighborhood --------------------------- {{1,0,1},{1,1,1},{0,1,1}} , , , , , , , ST_SetValue Returns modified raster resulting from setting the value of a given band in a given columnx, rowy pixel or the pixels that intersect a particular geometry. Band numbers start at 1 and assumed to be 1 if not specified. raster ST_SetValue raster rast integer bandnum geometry geom double precision newvalue raster ST_SetValue raster rast geometry geom double precision newvalue raster ST_SetValue raster rast integer bandnum integer columnx integer rowy double precision newvalue raster ST_SetValue raster rast integer columnx integer rowy double precision newvalue Returns modified raster resulting from setting the specified pixels' values to new value for the designed band given the raster's row and column or a geometry. If no band is specified, then band 1 is assumed. Enhanced: 2.1.0 Geometry variant of ST_SetValue() now supports any geometry type, not just point. The geometry variant is a wrapper around the geomval[] variant of ST_SetValues() -- Geometry example SELECT (foo.geomval).val, ST_AsText(ST_Union((foo.geomval).geom)) FROM (SELECT ST_DumpAsPolygons( ST_SetValue(rast,1, ST_Point(3427927.75, 5793243.95), 50) ) As geomval FROM dummy_rast where rid = 2) As foo WHERE (foo.geomval).val < 250 GROUP BY (foo.geomval).val; val | st_astext -----+------------------------------------------------------------------- 50 | POLYGON((3427927.75 5793244,3427927.75 5793243.95,3427927.8 579324 ... 249 | POLYGON((3427927.95 5793243.95,3427927.95 5793243.85,3427928 57932 ... -- Store the changed raster -- UPDATE dummy_rast SET rast = ST_SetValue(rast,1, ST_Point(3427927.75, 5793243.95),100) WHERE rid = 2 ; , ST_SetValues Returns modified raster resulting from setting the values of a given band. raster ST_SetValues raster rast integer nband integer columnx integer rowy double precision[][] newvalueset boolean[][] noset=NULL boolean keepnodata=FALSE raster ST_SetValues raster rast integer nband integer columnx integer rowy double precision[][] newvalueset double precision nosetvalue boolean keepnodata=FALSE raster ST_SetValues raster rast integer nband integer columnx integer rowy integer width integer height double precision newvalue boolean keepnodata=FALSE raster ST_SetValues raster rast integer columnx integer rowy integer width integer height double precision newvalue boolean keepnodata=FALSE raster ST_SetValues raster rast integer nband geomval[] geomvalset boolean keepnodata=FALSE Returns modified raster resulting from setting specified pixels to new value(s) for the designated band. If keepnodata is TRUE, those pixels whose values are NODATA will not be set with the corresponding value in newvalueset. For Variant 1, the specific pixels to be set are determined by the columnx, rowy pixel coordinates and the dimensions of the newvalueset array. noset can be used to prevent pixels with values present in newvalueset from being set (due to PostgreSQL not permitting ragged/jagged arrays). See example Variant 1. Variant 2 is like Variant 1 but with a simple double precision nosetvalue instead of a boolean noset array. Elements in newvalueset with the nosetvalue value with be skipped. See example Variant 2. For Variant 3, the specific pixels to be set are determined by the columnx, rowy pixel coordinates, width and height. See example Variant 3. Variant 4 is the same as Variant 3 with the exception that it assumes that the first band's pixels of rast will be set. For Variant 5, an array of is used to determine the specific pixels to be set. If all the geometries in the array are of type POINT or MULTIPOINT, the function uses a shortcut where the longitude and latitude of each point is used to set a pixel directly. Otherwise, the geometries are converted to rasters and then iterated through in one pass. See example Variant 5. Availability: 2.1.0 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 1 | 1 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 2, 2, ARRAY[[9, 9], [9, 9]]::double precision[][] ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 1 | 2 | 1 1 | 3 | 1 2 | 1 | 1 2 | 2 | 9 2 | 3 | 9 3 | 1 | 1 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 9 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 9 | | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 9 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 1, 1, ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][] ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 9 1 | 2 | 9 1 | 3 | 9 2 | 1 | 9 2 | 2 | 2 | 3 | 9 3 | 1 | 9 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 9 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 9 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 1, 1, ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][], ARRAY[[false], [true]]::boolean[][] ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 9 1 | 2 | 1 1 | 3 | 9 2 | 1 | 9 2 | 2 | 2 | 3 | 9 3 | 1 | 9 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | | 1 | 1 | | | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 9 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 1, 1, NULL ), 1, 1, 1, ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][], ARRAY[[false], [true]]::boolean[][], TRUE ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 | 2 | 1 1 | 3 | 9 2 | 1 | 9 2 | 2 | 2 | 3 | 9 3 | 1 | 9 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 1 | 1 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 1, 1, ARRAY[[-1, -1, -1], [-1, 9, 9], [-1, 9, 9]]::double precision[][], -1 ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 1 | 2 | 1 1 | 3 | 1 2 | 1 | 1 2 | 2 | 9 2 | 3 | 9 3 | 1 | 1 3 | 2 | 9 3 | 3 | 9 /* This example is like the previous one. Instead of nosetvalue = -1, nosetvalue = NULL The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 1 | 1 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 1, 1, ARRAY[[NULL, NULL, NULL], [NULL, 9, 9], [NULL, 9, 9]]::double precision[][], NULL::double precision ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 1 | 2 | 1 1 | 3 | 1 2 | 1 | 1 2 | 2 | 9 2 | 3 | 9 3 | 1 | 1 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 1 | 1 | + - + - + - + + - + - + - + | 1 | 1 | 1 | => | 1 | 9 | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 2, 2, 2, 2, 9 ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 1 | 2 | 1 1 | 3 | 1 2 | 1 | 1 2 | 2 | 9 2 | 3 | 9 3 | 1 | 1 3 | 2 | 9 3 | 3 | 9 /* The ST_SetValues() does the following... + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 1 | 1 | + - + - + - + + - + - + - + | 1 | | 1 | => | 1 | | 9 | + - + - + - + + - + - + - + | 1 | 1 | 1 | | 1 | 9 | 9 | + - + - + - + + - + - + - + */ SELECT (poly).x, (poly).y, (poly).val FROM ( SELECT ST_PixelAsPolygons( ST_SetValues( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0 ), 1, 2, 2, NULL ), 1, 2, 2, 2, 2, 9, TRUE ) ) AS poly ) foo ORDER BY 1, 2; x | y | val ---+---+----- 1 | 1 | 1 1 | 2 | 1 1 | 3 | 1 2 | 1 | 1 2 | 2 | 2 | 3 | 9 3 | 1 | 1 3 | 2 | 9 3 | 3 | 9 WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast ), bar AS ( SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry ) SELECT rid, gid, ST_DumpValues(ST_SetValue(rast, 1, geom, gid)) FROM foo t1 CROSS JOIN bar t2 ORDER BY rid, gid; rid | gid | st_dumpvalues -----+-----+--------------------------------------------------------------------------------------------------------------------------------------------- 1 | 1 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,1,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL}}") 1 | 2 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}") 1 | 3 | (1,"{{3,3,3,3,3},{3,NULL,NULL,NULL,NULL},{3,NULL,NULL,NULL,NULL},{3,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL}}") 1 | 4 | (1,"{{4,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,4}}") (4 rows) The following shows that geomvals later in the array can overwrite prior geomvals WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast ), bar AS ( SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry ) SELECT t1.rid, t2.gid, t3.gid, ST_DumpValues(ST_SetValues(rast, 1, ARRAY[ROW(t2.geom, t2.gid), ROW(t3.geom, t3.gid)]::geomval[])) FROM foo t1 CROSS JOIN bar t2 CROSS JOIN bar t3 WHERE t2.gid = 1 AND t3.gid = 2 ORDER BY t1.rid, t2.gid, t3.gid; rid | gid | gid | st_dumpvalues -----+-----+-----+--------------------------------------------------------------------------------------------------------------------- 1 | 1 | 2 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}") (1 row) This example is the opposite of the prior example WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast ), bar AS ( SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry ) SELECT t1.rid, t2.gid, t3.gid, ST_DumpValues(ST_SetValues(rast, 1, ARRAY[ROW(t2.geom, t2.gid), ROW(t3.geom, t3.gid)]::geomval[])) FROM foo t1 CROSS JOIN bar t2 CROSS JOIN bar t3 WHERE t2.gid = 2 AND t3.gid = 1 ORDER BY t1.rid, t2.gid, t3.gid; rid | gid | gid | st_dumpvalues -----+-----+-----+--------------------------------------------------------------------------------------------------------------------- 1 | 2 | 1 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,1,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}") (1 row) , , ST_DumpValues Get the values of the specified band as a 2-dimension array. setof record ST_DumpValues raster rast integer[] nband boolean exclude_nodata_value=true double precision[][] ST_DumpValues raster rast integer nband boolean exclude_nodata_value=true Get the values of the specified band as a 2-dimension array. If nband is NULL or not provided, all raster bands are processed. Availability: 2.1.0 WITH foo AS ( SELECT ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '32BF', 3, -9999), 3, '16BSI', 0, 0) AS rast ) SELECT (ST_DumpValues(rast)).* FROM foo; nband | valarray -------+------------------------------------------------------ 1 | {{1,1,1},{1,1,1},{1,1,1}} 2 | {{3,3,3},{3,3,3},{3,3,3}} 3 | {{NULL,NULL,NULL},{NULL,NULL,NULL},{NULL,NULL,NULL}} (3 rows) WITH foo AS ( SELECT ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 2, '32BF', 3, -9999), 3, '16BSI', 0, 0) AS rast ) SELECT (ST_DumpValues(rast, ARRAY[3, 1])).* FROM foo; nband | valarray -------+------------------------------------------------------ 3 | {{NULL,NULL,NULL},{NULL,NULL,NULL},{NULL,NULL,NULL}} 1 | {{1,1,1},{1,1,1},{1,1,1}} (2 rows) , , ST_PixelOfValue Get the columnx, rowy coordinates of the pixel whose value equals the search value. setof record ST_PixelOfValue raster rast integer nband double precision[] search boolean exclude_nodata_value=true setof record ST_PixelOfValue raster rast double precision[] search boolean exclude_nodata_value=true setof record ST_PixelOfValue raster rast integer nband double precision search boolean exclude_nodata_value=true setof record ST_PixelOfValue raster rast double precision search boolean exclude_nodata_value=true Get the columnx, rowy coordinates of the pixel whose value equals the search value. If no band is specified, then band 1 is assumed. Availability: 2.1.0 SELECT (pixels).* FROM ( SELECT ST_PixelOfValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0), '8BUI'::text, 1, 0 ), 1, 1, 0 ), 2, 3, 0 ), 3, 5, 0 ), 4, 2, 0 ), 5, 4, 255 ) , 1, ARRAY[1, 255]) AS pixels ) AS foo val | x | y -----+---+--- 1 | 1 | 2 1 | 1 | 3 1 | 1 | 4 1 | 1 | 5 1 | 2 | 1 1 | 2 | 2 1 | 2 | 4 1 | 2 | 5 1 | 3 | 1 1 | 3 | 2 1 | 3 | 3 1 | 3 | 4 1 | 4 | 1 1 | 4 | 3 1 | 4 | 4 1 | 4 | 5 1 | 5 | 1 1 | 5 | 2 1 | 5 | 3 255 | 5 | 4 1 | 5 | 5 ST_SetGeoReference Set Georeference 6 georeference parameters in a single call. Numbers should be separated by white space. Accepts inputs in GDAL or ESRI format. Default is GDAL. raster ST_SetGeoReference raster rast text georefcoords text format=GDAL raster ST_SetGeoReference raster rast double precision upperleftx double precision upperlefty double precision scalex double precision scaley double precision skewx double precision skewy Set Georeference 6 georeference parameters in a single call. Accepts inputs in 'GDAL' or 'ESRI' format. Default is GDAL. If 6 coordinates are not provided will return null. Difference between format representations is as follows: GDAL: scalex skewy skewx scaley upperleftx upperlefty ESRI: scalex skewy skewx scaley upperleftx + scalex*0.5 upperlefty + scaley*0.5 If the raster has out-db bands, changing the georeference may result in incorrect access of the band's externally stored data. Enhanced: 2.1.0 Addition of ST_SetGeoReference(raster, double precision, ...) variant WITH foo AS ( SELECT ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0) AS rast ) SELECT 0 AS rid, (ST_Metadata(rast)).* FROM foo UNION ALL SELECT 1, (ST_Metadata(ST_SetGeoReference(rast, '10 0 0 -10 0.1 0.1', 'GDAL'))).* FROM foo UNION ALL SELECT 2, (ST_Metadata(ST_SetGeoReference(rast, '10 0 0 -10 5.1 -4.9', 'ESRI'))).* FROM foo UNION ALL SELECT 3, (ST_Metadata(ST_SetGeoReference(rast, 1, 1, 10, -10, 0.001, 0.001))).* FROM foo rid | upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands -----+--------------------+--------------------+-------+--------+--------+--------+-------+-------+------+---------- 0 | 0 | 0 | 5 | 5 | 1 | -1 | 0 | 0 | 0 | 0 1 | 0.1 | 0.1 | 5 | 5 | 10 | -10 | 0 | 0 | 0 | 0 2 | 0.0999999999999996 | 0.0999999999999996 | 5 | 5 | 10 | -10 | 0 | 0 | 0 | 0 3 | 1 | 1 | 5 | 5 | 10 | -10 | 0.001 | 0.001 | 0 | 0 , , , , ST_SetRotation Set the rotation of the raster in radian. float8 ST_SetRotation raster rast float8 rotation Uniformly rotate the raster. Rotation is in radian. Refer to World File for more details. SELECT ST_ScaleX(rast1), ST_ScaleY(rast1), ST_SkewX(rast1), ST_SkewY(rast1), ST_ScaleX(rast2), ST_ScaleY(rast2), ST_SkewX(rast2), ST_SkewY(rast2) FROM ( SELECT ST_SetRotation(rast, 15) AS rast1, rast as rast2 FROM dummy_rast ) AS foo; st_scalex | st_scaley | st_skewx | st_skewy | st_scalex | st_scaley | st_skewx | st_skewy ---------------------+---------------------+--------------------+--------------------+-----------+-----------+----------+---------- -1.51937582571764 | -2.27906373857646 | 1.95086352047135 | 1.30057568031423 | 2 | 3 | 0 | 0 -0.0379843956429411 | -0.0379843956429411 | 0.0325143920078558 | 0.0325143920078558 | 0.05 | -0.05 | 0 | 0 , , , , ST_SetScale Sets the X and Y size of pixels in units of coordinate reference system. Number units/pixel width/height. raster ST_SetScale raster rast float8 xy raster ST_SetScale raster rast float8 x float8 y Sets the X and Y size of pixels in units of coordinate reference system. Number units/pixel width/height. If only one unit passed in, assumed X and Y are the same number. ST_SetScale is different from in that ST_SetScale do not resample the raster to match the raster extent. It only changes the metadata (or georeference) of the raster to correct an originally mis-specified scaling. ST_Rescale results in a raster having different width and height computed to fit the geographic extent of the input raster. ST_SetScale do not modify the width, nor the height of the raster. Changed: 2.0.0 In WKTRaster versions this was called ST_SetPixelSize. This was changed in 2.0.0. UPDATE dummy_rast SET rast = ST_SetScale(rast, 1.5) WHERE rid = 2; SELECT ST_ScaleX(rast) As pixx, ST_ScaleY(rast) As pixy, Box3D(rast) As newbox FROM dummy_rast WHERE rid = 2; pixx | pixy | newbox ------+------+---------------------------------------------- 1.5 | 1.5 | BOX(3427927.75 5793244 0, 3427935.25 5793251.5 0) UPDATE dummy_rast SET rast = ST_SetScale(rast, 1.5, 0.55) WHERE rid = 2; SELECT ST_ScaleX(rast) As pixx, ST_ScaleY(rast) As pixy, Box3D(rast) As newbox FROM dummy_rast WHERE rid = 2; pixx | pixy | newbox ------+------+-------------------------------------------- 1.5 | 0.55 | BOX(3427927.75 5793244 0,3427935.25 5793247 0) , , ST_SetSkew Sets the georeference X and Y skew (or rotation parameter). If only one is passed in, sets X and Y to the same value. raster ST_SetSkew raster rast float8 skewxy raster ST_SetSkew raster rast float8 skewx float8 skewy Sets the georeference X and Y skew (or rotation parameter). If only one is passed in, sets X and Y to the same value. Refer to World File for more details. -- Example 1 UPDATE dummy_rast SET rast = ST_SetSkew(rast,1,2) WHERE rid = 1; SELECT rid, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy, ST_GeoReference(rast) as georef FROM dummy_rast WHERE rid = 1; rid | skewx | skewy | georef ----+-------+-------+-------------- 1 | 1 | 2 | 2.0000000000 : 2.0000000000 : 1.0000000000 : 3.0000000000 : 0.5000000000 : 0.5000000000 -- Example 2 set both to same number: UPDATE dummy_rast SET rast = ST_SetSkew(rast,0) WHERE rid = 1; SELECT rid, ST_SkewX(rast) As skewx, ST_SkewY(rast) As skewy, ST_GeoReference(rast) as georef FROM dummy_rast WHERE rid = 1; rid | skewx | skewy | georef -----+-------+-------+-------------- 1 | 0 | 0 | 2.0000000000 : 0.0000000000 : 0.0000000000 : 3.0000000000 : 0.5000000000 : 0.5000000000 , , , ST_SetSRID Sets the SRID of a raster to a particular integer srid defined in the spatial_ref_sys table. raster ST_SetSRID raster rast integer srid Sets the SRID on a raster to a particular integer value. This function does not transform the raster in any way - it simply sets meta data defining the spatial ref of the coordinate reference system that it's currently in. Useful for transformations later. , ST_SetUpperLeft Sets the value of the upper left corner of the pixel to projected X and Y coordinates. raster ST_SetUpperLeft raster rast double precision x double precision y Set the value of the upper left corner of raster to the projected X coordinates SELECT ST_SetUpperLeft(rast,-71.01,42.37) FROM dummy_rast WHERE rid = 2; , ST_Resample Resample a raster using a specified resampling algorithm, new dimensions, an arbitrary grid corner and a set of raster georeferencing attributes defined or borrowed from another raster. raster ST_Resample raster rast integer width integer height double precision gridx=NULL double precision gridy=NULL double precision skewx=0 double precision skewy=0 text algorithm=NearestNeighbour double precision maxerr=0.125 raster ST_Resample raster rast double precision scalex=0 double precision scaley=0 double precision gridx=NULL double precision gridy=NULL double precision skewx=0 double precision skewy=0 text algorithm=NearestNeighbor double precision maxerr=0.125 raster ST_Resample raster rast raster ref text algorithm=NearestNeighbour double precision maxerr=0.125 boolean usescale=true raster ST_Resample raster rast raster ref boolean usescale text algorithm=NearestNeighbour double precision maxerr=0.125 Resample a raster using a specified resampling algorithm, new dimensions (width & height), a grid corner (gridx & gridy) and a set of raster georeferencing attributes (scalex, scaley, skewx & skewy) defined or borrowed from another raster. If using a reference raster, the two rasters must have the same SRID. New pixel values are computed using the NearestNeighbor (English or American spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. Default is NearestNeighbor which is the fastest but produce the worst interpolation. A maxerror percent of 0.125 is used if no maxerr is specified. Refer to: GDAL Warp resampling methods for more details. Availability: 2.0.0 Requires GDAL 1.6.1+ Changed: 2.1.0 Parameter srid removed. Variants with a reference raster no longer applies the reference raster's SRID. Use ST_Transform() to reproject raster. Works on rasters with no SRID. SELECT ST_Width(orig) AS orig_width, ST_Width(reduce_100) AS new_width FROM ( SELECT rast AS orig, ST_Resample(rast,100,100) AS reduce_100 FROM aerials.boston WHERE ST_Intersects(rast, ST_Transform( ST_MakeEnvelope(-71.128, 42.2392,-71.1277, 42.2397, 4326),26986) ) LIMIT 1 ) AS foo; orig_width | new_width ------------+------------- 200 | 100 , , ST_Rescale Resample a raster by adjusting only its scale (or pixel size). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. Default is NearestNeighbor. raster ST_Rescale raster rast double precision scalexy text algorithm=NearestNeighbour double precision maxerr=0.125 raster ST_Rescale raster rast double precision scalex double precision scaley text algorithm=NearestNeighbour double precision maxerr=0.125 Resample a raster by adjusting only its scale (or pixel size). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. The default is NearestNeighbor which is the fastest but results in the worst interpolation. scalex and scaley define the new pixel size. scaley must often be negative to get well oriented raster. When the new scalex or scaley is not a divisor of the raster width or height, the extent of the resulting raster is expanded to encompass the extent of the provided raster. If you want to be sure to retain exact input extent see A maxerror percent of 0.125 is used if no maxerr is specified. Refer to: GDAL Warp resampling methods for more details. ST_Rescale is different from in that ST_SetScale do not resample the raster to match the raster extent. ST_SetScale only changes the metadata (or georeference) of the raster to correct an originally mis-specified scaling. ST_Rescale results in a raster having different width and height computed to fit the geographic extent of the input raster. ST_SetScale do not modify the width, nor the height of the raster. Availability: 2.0.0 Requires GDAL 1.6.1+ Changed: 2.1.0 Works on rasters with no SRID A simple example rescaling a raster from a pixel size of 0.001 degree to a pixel size of 0.0015 degree. -- the original raster pixel size SELECT ST_PixelWidth(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0)) width width ---------- 0.001 -- the rescaled raster raster pixel size SELECT ST_PixelWidth(ST_Rescale(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0), 0.0015)) width width ---------- 0.0015 , , , , , ST_Reskew Resample a raster by adjusting only its skew (or rotation parameters). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. Default is NearestNeighbor. raster ST_Reskew raster rast double precision skewxy text algorithm=NearestNeighbour double precision maxerr=0.125 raster ST_Reskew raster rast double precision skewx double precision skewy text algorithm=NearestNeighbour double precision maxerr=0.125 Resample a raster by adjusting only its skew (or rotation parameters). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. The default is NearestNeighbor which is the fastest but results in the worst interpolation. skewx and skewy define the new skew. The extent of the new raster will encompass the extent of the provided raster. A maxerror percent of 0.125 if no maxerr is specified. Refer to: GDAL Warp resampling methods for more details. ST_Reskew is different from in that ST_SetSkew do not resample the raster to match the raster extent. ST_SetSkew only changes the metadata (or georeference) of the raster to correct an originally mis-specified skew. ST_Reskew results in a raster having different width and height computed to fit the geographic extent of the input raster. ST_SetSkew do not modify the width, nor the height of the raster. Availability: 2.0.0 Requires GDAL 1.6.1+ Changed: 2.1.0 Works on rasters with no SRID A simple example reskewing a raster from a skew of 0.0 to a skew of 0.0015. -- the original raster pixel size SELECT ST_Rotation(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0)) -- the rescaled raster raster pixel size SELECT ST_Rotation(ST_Reskew(ST_AddBand(ST_MakeEmptyRaster(100, 100, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0), 0.0015)) , , , , , , ST_SnapToGrid Resample a raster by snapping it to a grid. New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. Default is NearestNeighbor. raster ST_SnapToGrid raster rast double precision gridx double precision gridy text algorithm=NearestNeighbour double precision maxerr=0.125 double precision scalex=DEFAULT 0 double precision scaley=DEFAULT 0 raster ST_SnapToGrid raster rast double precision gridx double precision gridy double precision scalex double precision scaley text algorithm=NearestNeighbour double precision maxerr=0.125 raster ST_SnapToGrid raster rast double precision gridx double precision gridy double precision scalexy text algorithm=NearestNeighbour double precision maxerr=0.125 Resample a raster by snapping it to a grid defined by an arbitrary pixel corner (gridx & gridy) and optionally a pixel size (scalex & scaley). New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. The default is NearestNeighbor which is the fastest but results in the worst interpolation. gridx and gridy define any arbitrary pixel corner of the new grid. This is not necessarily the upper left corner of the new raster and it does not have to be inside or on the edge of the new raster extent. You can optionnal define the pixel size of the new grid with scalex and scaley. The extent of the new raster will encompass the extent of the provided raster. A maxerror percent of 0.125 if no maxerr is specified. Refer to: GDAL Warp resampling methods for more details. Use if you need more control over the grid parameters. Availability: 2.0.0 Requires GDAL 1.6.1+ Changed: 2.1.0 Works on rasters with no SRID A simple example snapping a raster to a slightly different grid. -- the original raster pixel size SELECT ST_UpperLeftX(ST_AddBand(ST_MakeEmptyRaster(10, 10, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0)) -- the rescaled raster raster pixel size SELECT ST_UpperLeftX(ST_SnapToGrid(ST_AddBand(ST_MakeEmptyRaster(10, 10, 0, 0, 0.001, -0.001, 0, 0, 4269), '8BUI'::text, 1, 0), 0.0002, 0.0002)) , , , ST_Resize Resize a raster to a new width/height raster ST_Resize raster rast integer width integer height text algorithm=NearestNeighbor double precision maxerr=0.125 raster ST_Resize raster rast double precision percentwidth double precision percentheight text algorithm=NearestNeighbor double precision maxerr=0.125 raster ST_Resize raster rast text width text height text algorithm=NearestNeighbor double precision maxerr=0.125 Resize a raster to a new width/height. The new width/height can be specified in exact number of pixels or a percentage of the raster's width/height. The extent of the the new raster will be the same as the extent of the provided raster. New pixel values are computed using the NearestNeighbor (english or american spelling), Bilinear, Cubic, CubicSpline or Lanczos resampling algorithm. The default is NearestNeighbor which is the fastest but results in the worst interpolation. Variant 1 expects the actual width/height of the output raster. Variant 2 expects decimal values between zero (0) and one (1) indicating the percentage of the input raster's width/height. Variant 3 takes either the actual width/height of the output raster or a textual percentage ("20%") indicating the percentage of the input raster's width/height. Availability: 2.1.0 Requires GDAL 1.6.1+ WITH foo AS( SELECT 1 AS rid, ST_Resize( ST_AddBand( ST_MakeEmptyRaster(1000, 1000, 0, 0, 1, -1, 0, 0, 0) , 1, '8BUI', 255, 0 ) , '50%', '500') AS rast UNION ALL SELECT 2 AS rid, ST_Resize( ST_AddBand( ST_MakeEmptyRaster(1000, 1000, 0, 0, 1, -1, 0, 0, 0) , 1, '8BUI', 255, 0 ) , 500, 100) AS rast UNION ALL SELECT 3 AS rid, ST_Resize( ST_AddBand( ST_MakeEmptyRaster(1000, 1000, 0, 0, 1, -1, 0, 0, 0) , 1, '8BUI', 255, 0 ) , 0.25, 0.9) AS rast ), bar AS ( SELECT rid, ST_Metadata(rast) AS meta, rast FROM foo ) SELECT rid, (meta).* FROM bar rid | upperleftx | upperlefty | width | height | scalex | scaley | skewx | skewy | srid | numbands -----+------------+------------+-------+--------+--------+--------+-------+-------+------+---------- 1 | 0 | 0 | 500 | 500 | 1 | -1 | 0 | 0 | 0 | 1 2 | 0 | 0 | 500 | 100 | 1 | -1 | 0 | 0 | 0 | 1 3 | 0 | 0 | 250 | 900 | 1 | -1 | 0 | 0 | 0 | 1 (3 rows) , , , ST_Transform Reprojects a raster in a known spatial reference system to another known spatial reference system using specified resampling algorithm. Options are NearestNeighbor, Bilinear, Cubic, CubicSpline, Lanczos defaulting to NearestNeighbor. raster ST_Transform raster rast integer srid text algorithm=NearestNeighbor double precision maxerr=0.125 double precision scalex double precision scaley raster ST_Transform raster rast integer srid double precision scalex double precision scaley text algorithm=NearestNeighbor double precision maxerr=0.125 raster ST_Transform raster rast raster alignto text algorithm=NearestNeighbor double precision maxerr=0.125 Reprojects a raster in a known spatial reference system to another known spatial reference system using specified pixel warping algorithm. Uses 'NearestNeighbor' if no algorithm is specified and maxerror percent of 0.125 if no maxerr is specified. Algorithm options are: 'NearestNeighbor', 'Bilinear', 'Cubic', 'CubicSpline', and 'Lanczos'. Refer to: GDAL Warp resampling methods for more details. ST_Transform is often confused with ST_SetSRID(). ST_Transform actually changes the coordinates of a raster (and resamples the pixel values) from one spatial reference system to another, while ST_SetSRID() simply changes the SRID identifier of the raster. Unlike the other variants, Variant 3 requires a reference raster as alignto. The transformed raster will be transformed to the spatial reference system (SRID) of the reference raster and be aligned (ST_SameAlignment = TRUE) to the reference raster. If you find your transformation support is not working right, you may need to set the environment variable PROJSO to the .so or .dll projection library your PostGIS is using. This just needs to have the name of the file. So for example on windows, you would in Control Panel -> System -> Environment Variables add a system variable called PROJSO and set it to libproj.dll (if you are using proj 4.6.1). You'll have to restart your PostgreSQL service/daemon after this change. Availability: 2.0.0 Requires GDAL 1.6.1+ Enhanced: 2.1.0 Addition of ST_Transform(rast, alignto) variant SELECT ST_Width(mass_stm) As w_before, ST_Width(wgs_84) As w_after, ST_Height(mass_stm) As h_before, ST_Height(wgs_84) As h_after FROM ( SELECT rast As mass_stm, ST_Transform(rast,4326) As wgs_84 , ST_Transform(rast,4326, 'Bilinear') AS wgs_84_bilin FROM aerials.o_2_boston WHERE ST_Intersects(rast, ST_Transform(ST_MakeEnvelope(-71.128, 42.2392,-71.1277, 42.2397, 4326),26986) ) LIMIT 1) As foo; w_before | w_after | h_before | h_after ----------+---------+----------+--------- 200 | 228 | 200 | 170 original mass state plane meters (mass_stm) After transform to wgs 84 long lat (wgs_84) After transform to wgs 84 long lat with bilinear algorithm instead of NN default (wgs_84_bilin) The following shows the difference between using ST_Transform(raster, srid) and ST_Transform(raster, alignto) WITH foo AS ( SELECT 0 AS rid, ST_AddBand(ST_MakeEmptyRaster(2, 2, -500000, 600000, 100, -100, 0, 0, 2163), 1, '16BUI', 1, 0) AS rast UNION ALL SELECT 1, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499800, 600000, 100, -100, 0, 0, 2163), 1, '16BUI', 2, 0) AS rast UNION ALL SELECT 2, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499600, 600000, 100, -100, 0, 0, 2163), 1, '16BUI', 3, 0) AS rast UNION ALL SELECT 3, ST_AddBand(ST_MakeEmptyRaster(2, 2, -500000, 599800, 100, -100, 0, 0, 2163), 1, '16BUI', 10, 0) AS rast UNION ALL SELECT 4, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499800, 599800, 100, -100, 0, 0, 2163), 1, '16BUI', 20, 0) AS rast UNION ALL SELECT 5, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499600, 599800, 100, -100, 0, 0, 2163), 1, '16BUI', 30, 0) AS rast UNION ALL SELECT 6, ST_AddBand(ST_MakeEmptyRaster(2, 2, -500000, 599600, 100, -100, 0, 0, 2163), 1, '16BUI', 100, 0) AS rast UNION ALL SELECT 7, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499800, 599600, 100, -100, 0, 0, 2163), 1, '16BUI', 200, 0) AS rast UNION ALL SELECT 8, ST_AddBand(ST_MakeEmptyRaster(2, 2, -499600, 599600, 100, -100, 0, 0, 2163), 1, '16BUI', 300, 0) AS rast ), bar AS ( SELECT ST_Transform(rast, 4269) AS alignto FROM foo LIMIT 1 ), baz AS ( SELECT rid, rast, ST_Transform(rast, 4269) AS not_aligned, ST_Transform(rast, alignto) AS aligned FROM foo CROSS JOIN bar ) SELECT ST_SameAlignment(rast) AS rast, ST_SameAlignment(not_aligned) AS not_aligned, ST_SameAlignment(aligned) AS aligned FROM baz rast | not_aligned | aligned ------+-------------+--------- t | f | t , ST_SetBandNoDataValue Sets the value for the given band that represents no data. Band 1 is assumed if no band is specified. To mark a band as having no nodata value, set the nodata value = NULL. raster ST_SetBandNoDataValue raster rast double precision nodatavalue raster ST_SetBandNoDataValue raster rast integer band double precision nodatavalue boolean forcechecking=false Sets the value that represents no data for the band. Band 1 is assumed if not specified. This will affect results from , , and the ST_PixelAs...() functions. -- change just first band no data value UPDATE dummy_rast SET rast = ST_SetBandNoDataValue(rast,1, 254) WHERE rid = 2; -- change no data band value of bands 1,2,3 UPDATE dummy_rast SET rast = ST_SetBandNoDataValue( ST_SetBandNoDataValue( ST_SetBandNoDataValue( rast,1, 254) ,2,99), 3,108) WHERE rid = 2; -- wipe out the nodata value this will ensure all pixels are considered for all processing functions UPDATE dummy_rast SET rast = ST_SetBandNoDataValue(rast,1, NULL) WHERE rid = 2; , ST_SetBandIsNoData Sets the isnodata flag of the band to TRUE. raster ST_SetBandIsNoData raster rast integer band=1 Sets the isnodata flag for the band to true. Band 1 is assumed if not specified. This function should be called only when the flag is considered dirty. That is, when the result calling is different using TRUE as last argument and without using it Availability: 2.0.0 -- Create dummy table with one raster column create table dummy_rast (rid integer, rast raster); -- Add raster with two bands, one pixel/band. In the first band, nodatavalue = pixel value = 3. -- In the second band, nodatavalue = 13, pixel value = 4 insert into dummy_rast values(1, ( '01' -- little endian (uint8 ndr) || '0000' -- version (uint16 0) || '0200' -- nBands (uint16 0) || '17263529ED684A3F' -- scaleX (float64 0.000805965234044584) || 'F9253529ED684ABF' -- scaleY (float64 -0.00080596523404458) || '1C9F33CE69E352C0' -- ipX (float64 -75.5533328537098) || '718F0E9A27A44840' -- ipY (float64 49.2824585505576) || 'ED50EB853EC32B3F' -- skewX (float64 0.000211812383858707) || '7550EB853EC32B3F' -- skewY (float64 0.000211812383858704) || 'E6100000' -- SRID (int32 4326) || '0100' -- width (uint16 1) || '0100' -- height (uint16 1) || '4' -- hasnodatavalue set to true, isnodata value set to false (when it should be true) || '2' -- first band type (4BUI) || '03' -- novalue==3 || '03' -- pixel(0,0)==3 (same that nodata) || '0' -- hasnodatavalue set to false || '5' -- second band type (16BSI) || '0D00' -- novalue==13 || '0400' -- pixel(0,0)==4 )::raster ); select st_bandisnodata(rast, 1) from dummy_rast where rid = 1; -- Expected false select st_bandisnodata(rast, 1, TRUE) from dummy_rast where rid = 1; -- Expected true -- The isnodata flag is dirty. We are going to set it to true update dummy_rast set rast = st_setbandisnodata(rast, 1) where rid = 1; select st_bandisnodata(rast, 1) from dummy_rast where rid = 1; -- Expected true , , , ST_Count Returns the number of pixels in a given band of a raster or raster coverage. If no band is specified defaults to band 1. If exclude_nodata_value is set to true, will only count pixels that are not equal to the nodata value. bigint ST_Count raster rast integer nband=1 boolean exclude_nodata_value=true bigint ST_Count raster rast boolean exclude_nodata_value bigint ST_Count text rastertable text rastercolumn integer nband=1 boolean exclude_nodata_value=true bigint ST_Count text rastertable text rastercolumn boolean exclude_nodata_value Returns the number of pixels in a given band of a raster or raster coverage. If no band is specified nband defaults to 1. If exclude_nodata_value is set to true, will only count pixels with value not equal to the nodata value of the raster. Set exclude_nodata_value to false to get count all pixels Availability: 2.0.0 The ST_Count(rastertable, rastercolumn, ...) variants are deprecated as of 2.2.0. Use instead. --example will count all pixels not 249 and one will count all pixels. -- SELECT rid, ST_Count(ST_SetBandNoDataValue(rast,249)) As exclude_nodata, ST_Count(ST_SetBandNoDataValue(rast,249),false) As include_nodata FROM dummy_rast WHERE rid=2; rid | exclude_nodata | include_nodata -----+----------------+---------------- 2 | 23 | 25 , , ST_CountAgg Aggregate. Returns the number of pixels in a given band of a set of rasters. If no band is specified defaults to band 1. If exclude_nodata_value is set to true, will only count pixels that are not equal to the NODATA value. bigint ST_CountAgg raster rast integer nband boolean exclude_nodata_value double precision sample_percent bigint ST_CountAgg raster rast integer nband boolean exclude_nodata_value bigint ST_CountAgg raster rast boolean exclude_nodata_value Returns the number of pixels in a given band of a set of rasters. If no band is specified nband defaults to 1. If exclude_nodata_value is set to true, will only count pixels with value not equal to the NODATA value of the raster. Set exclude_nodata_value to false to get count all pixels By default will sample all pixels. To get faster response, set sample_percent to value between zero (0) and one (1) Availability: 2.2.0 WITH foo AS ( SELECT rast.rast FROM ( SELECT ST_SetValue( ST_SetValue( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(10, 10, 10, 10, 2, 2, 0, 0,0) , 1, '64BF', 0, 0 ) , 1, 1, 1, -10 ) , 1, 5, 4, 0 ) , 1, 5, 5, 3.14159 ) AS rast ) AS rast FULL JOIN ( SELECT generate_series(1, 10) AS id ) AS id ON 1 = 1 ) SELECT ST_CountAgg(rast, 1, TRUE) FROM foo; st_countagg ------------- 20 (1 row) , , ST_Histogram Returns a set of record summarizing a raster or raster coverage data distribution separate bin ranges. Number of bins are autocomputed if not specified. SETOF record ST_Histogram raster rast integer nband=1 boolean exclude_nodata_value=true integer bins=autocomputed double precision[] width=NULL boolean right=false SETOF record ST_Histogram raster rast integer nband integer bins double precision[] width=NULL boolean right=false SETOF record ST_Histogram raster rast integer nband boolean exclude_nodata_value integer bins boolean right SETOF record ST_Histogram raster rast integer nband integer bins boolean right SETOF record ST_Histogram text rastertable text rastercolumn integer nband integer bins boolean right SETOF record ST_Histogram text rastertable text rastercolumn integer nband boolean exclude_nodata_value integer bins boolean right SETOF record ST_Histogram text rastertable text rastercolumn integer nband=1 boolean exclude_nodata_value=true integer bins=autocomputed double precision[] width=NULL boolean right=false SETOF record ST_Histogram text rastertable text rastercolumn integer nband=1 integer bins double precision[] width=NULL boolean right=false Returns set of records consisting of min, max, count, percent for a given raster band for each bin. If no band is specified nband defaults to 1. By default only considers pixel values not equal to the nodata value . Set exclude_nodata_value to false to get count all pixels. width double precision[] width: an array indicating the width of each category/bin. If the number of bins is greater than the number of widths, the widths are repeated. Example: 9 bins, widths are [a, b, c] will have the output be [a, b, c, a, b, c, a, b, c] bins integer Number of breakouts -- this is the number of records you'll get back from the function if specified. If not specified then the number of breakouts is autocomputed. right boolean compute the histogram from the right rather than from the left (default). This changes the criteria for evaluating a value x from [a, b) to (a, b] Availability: 2.0.0 SELECT band, (stats).* FROM (SELECT rid, band, ST_Histogram(rast, band) As stats FROM dummy_rast CROSS JOIN generate_series(1,3) As band WHERE rid=2) As foo; band | min | max | count | percent ------+-------+-------+-------+--------- 1 | 249 | 250 | 2 | 0.08 1 | 250 | 251 | 2 | 0.08 1 | 251 | 252 | 1 | 0.04 1 | 252 | 253 | 2 | 0.08 1 | 253 | 254 | 18 | 0.72 2 | 78 | 113.2 | 11 | 0.44 2 | 113.2 | 148.4 | 4 | 0.16 2 | 148.4 | 183.6 | 4 | 0.16 2 | 183.6 | 218.8 | 1 | 0.04 2 | 218.8 | 254 | 5 | 0.2 3 | 62 | 100.4 | 11 | 0.44 3 | 100.4 | 138.8 | 5 | 0.2 3 | 138.8 | 177.2 | 4 | 0.16 3 | 177.2 | 215.6 | 1 | 0.04 3 | 215.6 | 254 | 4 | 0.16 SELECT (stats).* FROM (SELECT rid, ST_Histogram(rast, 2,6) As stats FROM dummy_rast WHERE rid=2) As foo; min | max | count | percent ------------+------------+-------+--------- 78 | 107.333333 | 9 | 0.36 107.333333 | 136.666667 | 6 | 0.24 136.666667 | 166 | 0 | 0 166 | 195.333333 | 4 | 0.16 195.333333 | 224.666667 | 1 | 0.04 224.666667 | 254 | 5 | 0.2 (6 rows) -- Same as previous but we explicitly control the pixel value range of each bin. SELECT (stats).* FROM (SELECT rid, ST_Histogram(rast, 2,6,ARRAY[0.5,1,4,100,5]) As stats FROM dummy_rast WHERE rid=2) As foo; min | max | count | percent -------+-------+-------+---------- 78 | 78.5 | 1 | 0.08 78.5 | 79.5 | 1 | 0.04 79.5 | 83.5 | 0 | 0 83.5 | 183.5 | 17 | 0.0068 183.5 | 188.5 | 0 | 0 188.5 | 254 | 6 | 0.003664 (6 rows) , , ST_Quantile Compute quantiles for a raster or raster table coverage in the context of the sample or population. Thus, a value could be examined to be at the raster's 25%, 50%, 75% percentile. SETOF record ST_Quantile raster rast integer nband=1 boolean exclude_nodata_value=true double precision[] quantiles=NULL SETOF record ST_Quantile raster rast double precision[] quantiles SETOF record ST_Quantile raster rast integer nband double precision[] quantiles double precision ST_Quantile raster rast double precision quantile double precision ST_Quantile raster rast boolean exclude_nodata_value double precision quantile=NULL double precision ST_Quantile raster rast integer nband double precision quantile double precision ST_Quantile raster rast integer nband boolean exclude_nodata_value double precision quantile double precision ST_Quantile raster rast integer nband double precision quantile SETOF record ST_Quantile text rastertable text rastercolumn integer nband=1 boolean exclude_nodata_value=true double precision[] quantiles=NULL SETOF record ST_Quantile text rastertable text rastercolumn integer nband double precision[] quantiles Compute quantiles for a raster or raster table coverage in the context of the sample or population. Thus, a value could be examined to be at the raster's 25%, 50%, 75% percentile. If exclude_nodata_value is set to false, will also count pixels with no data. Availability: 2.0.0 UPDATE dummy_rast SET rast = ST_SetBandNoDataValue(rast,249) WHERE rid=2; --Example will consider only pixels of band 1 that are not 249 and in named quantiles -- SELECT (pvq).* FROM (SELECT ST_Quantile(rast, ARRAY[0.25,0.75]) As pvq FROM dummy_rast WHERE rid=2) As foo ORDER BY (pvq).quantile; quantile | value ----------+------- 0.25 | 253 0.75 | 254 SELECT ST_Quantile(rast, 0.75) As value FROM dummy_rast WHERE rid=2; value ------ 254 --real live example. Quantile of all pixels in band 2 intersecting a geometry SELECT rid, (ST_Quantile(rast,2)).* As pvc FROM o_4_boston WHERE ST_Intersects(rast, ST_GeomFromText('POLYGON((224486 892151,224486 892200,224706 892200,224706 892151,224486 892151))',26986) ) ORDER BY value, quantile,rid ; rid | quantile | value -----+----------+------- 1 | 0 | 0 2 | 0 | 0 14 | 0 | 1 15 | 0 | 2 14 | 0.25 | 37 1 | 0.25 | 42 15 | 0.25 | 47 2 | 0.25 | 50 14 | 0.5 | 56 1 | 0.5 | 64 15 | 0.5 | 66 2 | 0.5 | 77 14 | 0.75 | 81 15 | 0.75 | 87 1 | 0.75 | 94 2 | 0.75 | 106 14 | 1 | 199 1 | 1 | 244 2 | 1 | 255 15 | 1 | 255 , , , ST_SummaryStats Returns summarystats consisting of count, sum, mean, stddev, min, max for a given raster band of a raster or raster coverage. Band 1 is assumed is no band is specified. summarystats ST_SummaryStats raster rast boolean exclude_nodata_value summarystats ST_SummaryStats raster rast integer nband boolean exclude_nodata_value summarystats ST_SummaryStats text rastertable text rastercolumn boolean exclude_nodata_value summarystats ST_SummaryStats text rastertable text rastercolumn integer nband=1 boolean exclude_nodata_value=true Returns consisting of count, sum, mean, stddev, min, max for a given raster band of a raster or raster coverage. If no band is specified nband defaults to 1. By default only considers pixel values not equal to the nodata value. Set exclude_nodata_value to false to get count of all pixels. By default will sample all pixels. To get faster response, set sample_percent to lower than 1 Availability: 2.0.0 The ST_SummaryStats(rastertable, rastercolumn, ...) variants are deprecated as of 2.2.0. Use instead. SELECT rid, band, (stats).* FROM (SELECT rid, band, ST_SummaryStats(rast, band) As stats FROM dummy_rast CROSS JOIN generate_series(1,3) As band WHERE rid=2) As foo; rid | band | count | sum | mean | stddev | min | max -----+------+-------+------+------------+-----------+-----+----- 2 | 1 | 23 | 5821 | 253.086957 | 1.248061 | 250 | 254 2 | 2 | 25 | 3682 | 147.28 | 59.862188 | 78 | 254 2 | 3 | 25 | 3290 | 131.6 | 61.647384 | 62 | 254 This example took 574ms on PostGIS windows 64-bit with all of Boston Buildings and aerial Tiles (tiles each 150x150 pixels ~ 134,000 tiles), ~102,000 building records WITH -- our features of interest feat AS (SELECT gid As building_id, geom_26986 As geom FROM buildings AS b WHERE gid IN(100, 103,150) ), -- clip band 2 of raster tiles to boundaries of builds -- then get stats for these clipped regions b_stats AS (SELECT building_id, (stats).* FROM (SELECT building_id, ST_SummaryStats(ST_Clip(rast,2,geom)) As stats FROM aerials.boston INNER JOIN feat ON ST_Intersects(feat.geom,rast) ) As foo ) -- finally summarize stats SELECT building_id, SUM(count) As num_pixels , MIN(min) As min_pval , MAX(max) As max_pval , SUM(mean*count)/SUM(count) As avg_pval FROM b_stats WHERE count > 0 GROUP BY building_id ORDER BY building_id; building_id | num_pixels | min_pval | max_pval | avg_pval -------------+------------+----------+----------+------------------ 100 | 1090 | 1 | 255 | 61.0697247706422 103 | 655 | 7 | 182 | 70.5038167938931 150 | 895 | 2 | 252 | 185.642458100559 -- stats for each band -- SELECT band, (stats).* FROM (SELECT band, ST_SummaryStats('o_4_boston','rast', band) As stats FROM generate_series(1,3) As band) As foo; band | count | sum | mean | stddev | min | max ------+---------+--------+------------------+------------------+-----+----- 1 | 8450000 | 725799 | 82.7064349112426 | 45.6800222638537 | 0 | 255 2 | 8450000 | 700487 | 81.4197705325444 | 44.2161184161765 | 0 | 255 3 | 8450000 | 575943 | 74.682739408284 | 44.2143885481407 | 0 | 255 -- For a table -- will get better speed if set sampling to less than 100% -- Here we set to 25% and get a much faster answer SELECT band, (stats).* FROM (SELECT band, ST_SummaryStats('o_4_boston','rast', band,true,0.25) As stats FROM generate_series(1,3) As band) As foo; band | count | sum | mean | stddev | min | max ------+---------+--------+------------------+------------------+-----+----- 1 | 2112500 | 180686 | 82.6890480473373 | 45.6961043857248 | 0 | 255 2 | 2112500 | 174571 | 81.448503668639 | 44.2252623171821 | 0 | 255 3 | 2112500 | 144364 | 74.6765884023669 | 44.2014869384578 | 0 | 255 , , , ST_SummaryStatsAgg Aggregate. Returns summarystats consisting of count, sum, mean, stddev, min, max for a given raster band of a set of raster. Band 1 is assumed is no band is specified. summarystats ST_SummaryStatsAgg raster rast integer nband boolean exclude_nodata_value double precision sample_percent summarystats ST_SummaryStatsAgg raster rast boolean exclude_nodata_value double precision sample_percent summarystats ST_SummaryStatsAgg raster rast integer nband boolean exclude_nodata_value Returns consisting of count, sum, mean, stddev, min, max for a given raster band of a raster or raster coverage. If no band is specified nband defaults to 1. By default only considers pixel values not equal to the NODATA value. Set exclude_nodata_value to False to get count of all pixels. By default will sample all pixels. To get faster response, set sample_percent to value between 0 and 1 Availability: 2.2.0 WITH foo AS ( SELECT rast.rast FROM ( SELECT ST_SetValue( ST_SetValue( ST_SetValue( ST_AddBand( ST_MakeEmptyRaster(10, 10, 10, 10, 2, 2, 0, 0,0) , 1, '64BF', 0, 0 ) , 1, 1, 1, -10 ) , 1, 5, 4, 0 ) , 1, 5, 5, 3.14159 ) AS rast ) AS rast FULL JOIN ( SELECT generate_series(1, 10) AS id ) AS id ON 1 = 1 ) SELECT (stats).count, round((stats).sum::numeric, 3), round((stats).mean::numeric, 3), round((stats).stddev::numeric, 3), round((stats).min::numeric, 3), round((stats).max::numeric, 3) FROM ( SELECT ST_SummaryStatsAgg(rast, 1, TRUE, 1) AS stats FROM foo ) bar; count | round | round | round | round | round -------+---------+--------+-------+---------+------- 20 | -68.584 | -3.429 | 6.571 | -10.000 | 3.142 (1 row) , , , ST_ValueCount Returns a set of records containing a pixel band value and count of the number of pixels in a given band of a raster (or a raster coverage) that have a given set of values. If no band is specified defaults to band 1. By default nodata value pixels are not counted. and all other values in the pixel are output and pixel band values are rounded to the nearest integer. SETOF record ST_ValueCount raster rast integer nband=1 boolean exclude_nodata_value=true double precision[] searchvalues=NULL double precision roundto=0 double precision OUT value integer OUT count SETOF record ST_ValueCount raster rast integer nband double precision[] searchvalues double precision roundto=0 double precision OUT value integer OUT count SETOF record ST_ValueCount raster rast double precision[] searchvalues double precision roundto=0 double precision OUT value integer OUT count bigint ST_ValueCount raster rast double precision searchvalue double precision roundto=0 bigint ST_ValueCount raster rast integer nband boolean exclude_nodata_value double precision searchvalue double precision roundto=0 bigint ST_ValueCount raster rast integer nband double precision searchvalue double precision roundto=0 SETOF record ST_ValueCount text rastertable text rastercolumn integer nband=1 boolean exclude_nodata_value=true double precision[] searchvalues=NULL double precision roundto=0 double precision OUT value integer OUT count SETOF record ST_ValueCount text rastertable text rastercolumn double precision[] searchvalues double precision roundto=0 double precision OUT value integer OUT count SETOF record ST_ValueCount text rastertable text rastercolumn integer nband double precision[] searchvalues double precision roundto=0 double precision OUT value integer OUT count bigintST_ValueCount text rastertable text rastercolumn integer nband boolean exclude_nodata_value double precision searchvalue double precision roundto=0 bigint ST_ValueCount text rastertable text rastercolumn double precision searchvalue double precision roundto=0 bigint ST_ValueCount text rastertable text rastercolumn integer nband double precision searchvalue double precision roundto=0 Returns a set of records with columns value count which contain the pixel band value and count of pixels in the raster tile or raster coverage of selected band. If no band is specified nband defaults to 1. If no searchvalues are specified, will return all pixel values found in the raster or raster coverage. If one searchvalue is given, will return an integer instead of records denoting the count of pixels having that pixel band value If exclude_nodata_value is set to false, will also count pixels with no data. Availability: 2.0.0 UPDATE dummy_rast SET rast = ST_SetBandNoDataValue(rast,249) WHERE rid=2; --Example will count only pixels of band 1 that are not 249. -- SELECT (pvc).* FROM (SELECT ST_ValueCount(rast) As pvc FROM dummy_rast WHERE rid=2) As foo ORDER BY (pvc).value; value | count -------+------- 250 | 2 251 | 1 252 | 2 253 | 6 254 | 12 -- Example will coount all pixels of band 1 including 249 -- SELECT (pvc).* FROM (SELECT ST_ValueCount(rast,1,false) As pvc FROM dummy_rast WHERE rid=2) As foo ORDER BY (pvc).value; value | count -------+------- 249 | 2 250 | 2 251 | 1 252 | 2 253 | 6 254 | 12 -- Example will count only non-nodata value pixels of band 2 SELECT (pvc).* FROM (SELECT ST_ValueCount(rast,2) As pvc FROM dummy_rast WHERE rid=2) As foo ORDER BY (pvc).value; value | count -------+------- 78 | 1 79 | 1 88 | 1 89 | 1 96 | 1 97 | 1 98 | 1 99 | 2 112 | 2 : --real live example. Count all the pixels in an aerial raster tile band 2 intersecting a geometry -- and return only the pixel band values that have a count > 500 SELECT (pvc).value, SUM((pvc).count) As total FROM (SELECT ST_ValueCount(rast,2) As pvc FROM o_4_boston WHERE ST_Intersects(rast, ST_GeomFromText('POLYGON((224486 892151,224486 892200,224706 892200,224706 892151,224486 892151))',26986) ) ) As foo GROUP BY (pvc).value HAVING SUM((pvc).count) > 500 ORDER BY (pvc).value; value | total -------+----- 51 | 502 54 | 521 -- Just return count of pixels in each raster tile that have value of 100 of tiles that intersect a specific geometry -- SELECT rid, ST_ValueCount(rast,2,100) As count FROM o_4_boston WHERE ST_Intersects(rast, ST_GeomFromText('POLYGON((224486 892151,224486 892200,224706 892200,224706 892151,224486 892151))',26986) ) ; rid | count -----+------- 1 | 56 2 | 95 14 | 37 15 | 64 , ST_AsBinary Return the Well-Known Binary (WKB) representation of the raster without SRID meta data. bytea ST_AsBinary raster rast boolean outasin=FALSE Returns the Binary representation of the raster. If outasin is TRUE, out-db bands are treated as in-db. This is useful in binary cursors to pull data out of the database without converting it to a string representation. By default, WKB output contains the external file path for out-db bands. If the client does not have access to the raster file underlying an out-db band, set outasin to TRUE. Enhanced: 2.1.0 Addition of outasin SELECT ST_AsBinary(rast) As rastbin FROM dummy_rast WHERE rid=1; rastbin --------------------------------------------------------------------------------- \001\000\000\000\000\000\000\000\000\000\000\000@\000\000\000\000\000\000\010@\ 000\000\000\000\000\000\340?\000\000\000\000\000\000\340?\000\000\000\000\000\00 0\000\000\000\000\000\000\000\000\000\000\012\000\000\000\012\000\024\000 ST_AsGDALRaster Return the raster tile in the designated GDAL Raster format. Raster formats are one of those supported by your compiled library. Use ST_GDALRasters() to get a list of formats supported by your library. bytea ST_AsGDALRaster raster rast text format text[] options=NULL integer srid=sameassource Returns the raster tile in the designated format. Arguments are itemized below: format format to output. This is dependent on the drivers compiled in your libgdal library. Generally available are 'JPEG', 'GTIff', 'PNG'. Use to get a list of formats supported by your library. options text array of GDAL options. Valid options are dependent on the format. Refer to GDAL Raster format options for more details. srs The proj4text or srtext (from spatial_ref_sys) to embed in the image Availability: 2.0.0 - requires GDAL >= 1.6.0. SELECT ST_AsGDALRaster(rast, 'JPEG') As rastjpg FROM dummy_rast WHERE rid=1; SELECT ST_AsGDALRaster(rast, 'JPEG', ARRAY['QUALITY=50']) As rastjpg FROM dummy_rast WHERE rid=2; SELECT ST_AsGDALRaster(rast, 'GTiff') As rastjpg FROM dummy_rast WHERE rid=2; -- Out GeoTiff with jpeg compression, 90% quality SELECT ST_AsGDALRaster(rast, 'GTiff', ARRAY['COMPRESS=JPEG', 'JPEG_QUALITY=90'], 4269) As rasttiff FROM dummy_rast WHERE rid=2; , , ST_AsJPEG Return the raster tile selected bands as a single Joint Photographic Exports Group (JPEG) image (byte array). If no band is specified and 1 or more than 3 bands, then only the first band is used. If only 3 bands then all 3 bands are used and mapped to RGB. bytea ST_AsJPEG raster rast text[] options=NULL bytea ST_AsJPEG raster rast integer nband integer quality bytea ST_AsJPEG raster rast integer nband text[] options=NULL bytea ST_AsJPEG raster rast integer[] nbands text[] options=NULL bytea ST_AsJPEG raster rast integer[] nbands integer quality Returns the selected bands of the raster as a single Joint Photographic Exports Group Image (JPEG). Use if you need to export as less common raster types. If no band is specified and 1 or more than 3 bands, then only the first band is used. If 3 bands then all 3 bands are used. There are many variants of the function with many options. These are itemized below: nband is for single band exports. nbands is an array of bands to export (note that max is 3 for JPEG) and the order of the bands is RGB. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue quality number from 0 to 100. The higher the number the crisper the image. options text Array of GDAL options as defined for JPEG (look at create_options for JPEG ). For JPEG valid ones are PROGRESSIVE ON or OFF and QUALITY a range from 0 to 100 and default to 75. Refer to GDAL Raster format options for more details. Availability: 2.0.0 - requires GDAL >= 1.6.0. -- output first 3 bands 75% quality SELECT ST_AsJPEG(rast) As rastjpg FROM dummy_rast WHERE rid=2; -- output only first band as 90% quality SELECT ST_AsJPEG(rast,1,90) As rastjpg FROM dummy_rast WHERE rid=2; -- output first 3 bands (but make band 2 Red, band 1 green, and band 3 blue, progressive and 90% quality SELECT ST_AsJPEG(rast,ARRAY[2,1,3],ARRAY['QUALITY=90','PROGRESSIVE=ON']) As rastjpg FROM dummy_rast WHERE rid=2; , , , , ST_AsPNG Return the raster tile selected bands as a single portable network graphics (PNG) image (byte array). If 1, 3, or 4 bands in raster and no bands are specified, then all bands are used. If more 2 or more than 4 bands and no bands specified, then only band 1 is used. Bands are mapped to RGB or RGBA space. bytea ST_AsPNG raster rast text[] options=NULL bytea ST_AsPNG raster rast integer nband integer compression bytea ST_AsPNG raster rast integer nband text[] options=NULL bytea ST_AsPNG raster rast integer[] nbands integer compression bytea ST_AsPNG raster rast integer[] nbands text[] options=NULL Returns the selected bands of the raster as a single Portable Network Graphics Image (PNG). Use if you need to export as less common raster types. If no band is specified, then the first 3 bands are exported. There are many variants of the function with many options. If no srid is specified then then srid of the raster is used. These are itemized below: nband is for single band exports. nbands is an array of bands to export (note that max is 3 for PNG) and the order of the bands is RGB. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue compression number from 1 to 9. The higher the number the greater the compression. options text Array of GDAL options as defined for PNG (look at create_options for PNG of ). For PNG valid one is only ZLEVEL (amount of time to spend on compression -- default 6) e.g. ARRAY['ZLEVEL=9']. WORLDFILE is not allowed since the function would have to output two outputs. Refer to GDAL Raster format options for more details. Availability: 2.0.0 - requires GDAL >= 1.6.0. SELECT ST_AsPNG(rast) As rastpng FROM dummy_rast WHERE rid=2; -- export the first 3 bands and map band 3 to Red, band 1 to Green, band 2 to blue SELECT ST_AsPNG(rast, ARRAY[3,1,2]) As rastpng FROM dummy_rast WHERE rid=2; , , , ST_AsTIFF Return the raster selected bands as a single TIFF image (byte array). If no band is specified, then will try to use all bands. bytea ST_AsTIFF raster rast text[] options='' integer srid=sameassource bytea ST_AsTIFF raster rast text compression='' integer srid=sameassource bytea ST_AsTIFF raster rast integer[] nbands text compression='' integer srid=sameassource bytea ST_AsTIFF raster rast integer[] nbands text[] options integer srid=sameassource Returns the selected bands of the raster as a single Tagged Image File Format (TIFF). If no band is specified, will try to use all bands. This is a wrapper around . Use if you need to export as less common raster types. There are many variants of the function with many options. If no spatial reference SRS text is present, the spatial reference of the raster is used. These are itemized below: nbands is an array of bands to export (note that max is 3 for PNG) and the order of the bands is RGB. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue compression Compression expression -- JPEG90 (or some other percent), LZW, JPEG, DEFLATE9. options text Array of GDAL create options as defined for GTiff (look at create_options for GTiff of ). or refer to GDAL Raster format options for more details. srid srid of spatial_ref_sys of the raster. This is used to populate the georeference information Availability: 2.0.0 - requires GDAL >= 1.6.0. SELECT ST_AsTIFF(rast, 'JPEG90') As rasttiff FROM dummy_rast WHERE rid=2; , , ST_Clip Returns the raster clipped by the input geometry. If band number not is specified, all bands are processed. If crop is not specified or TRUE, the output raster is cropped. raster ST_Clip raster rast integer[] nband geometry geom double precision[] nodataval=NULL boolean crop=TRUE raster ST_Clip raster rast integer nband geometry geom double precision nodataval boolean crop=TRUE raster ST_Clip raster rast integer nband geometry geom boolean crop raster ST_Clip raster rast geometry geom double precision[] nodataval=NULL boolean crop=TRUE raster ST_Clip raster rast geometry geom double precision nodataval boolean crop=TRUE raster ST_Clip raster rast geometry geom boolean crop Returns a raster that is clipped by the input geometry geom. If band index is not specified, all bands are processed. Rasters resulting from ST_Clip must have a nodata value assigned for areas clipped, one for each band. If none are provided and the input raster do not have a nodata value defined, nodata values of the resulting raster are set to ST_MinPossibleValue(ST_BandPixelType(rast, band)). When the number of nodata value in the array is smaller than the number of band, the last one in the array is used for the remaining bands. If the number of nodata value is greater than the number of band, the extra nodata values are ignored. All variants accepting an array of nodata values also accept a single value which will be assigned to each band. If crop is not specified, true is assumed meaning the output raster is cropped to the intersection of the geomand rast extents. If crop is set to false, the new raster gets the same extent as rast. Availability: 2.0.0 Enhanced: 2.1.0 Rewritten in C Examples here use Massachusetts aerial data available on MassGIS site MassGIS Aerial Orthos. Coordinates are in Massachusetts State Plane Meters. -- Clip the first band of an aerial tile by a 20 meter buffer. SELECT ST_Clip(rast, 1, ST_Buffer(ST_Centroid(ST_Envelope(rast)),20) ) from aerials.boston WHERE rid = 4; -- Demonstrate effect of crop on final dimensions of raster -- Note how final extent is clipped to that of the geometry -- if crop = true SELECT ST_XMax(ST_Envelope(ST_Clip(rast, 1, clipper, true))) As xmax_w_trim, ST_XMax(clipper) As xmax_clipper, ST_XMax(ST_Envelope(ST_Clip(rast, 1, clipper, false))) As xmax_wo_trim, ST_XMax(ST_Envelope(rast)) As xmax_rast_orig FROM (SELECT rast, ST_Buffer(ST_Centroid(ST_Envelope(rast)),6) As clipper FROM aerials.boston WHERE rid = 6) As foo; xmax_w_trim | xmax_clipper | xmax_wo_trim | xmax_rast_orig ------------------+------------------+------------------+------------------ 230657.436173996 | 230657.436173996 | 230666.436173996 | 230666.436173996 Full raster tile before clipping After Clipping -- Same example as before, but we need to set crop to false to be able to use ST_AddBand -- because ST_AddBand requires all bands be the same Width and height SELECT ST_AddBand(ST_Clip(rast, 1, ST_Buffer(ST_Centroid(ST_Envelope(rast)),20),false ), ARRAY[ST_Band(rast,2),ST_Band(rast,3)] ) from aerials.boston WHERE rid = 6; Full raster tile before clipping After Clipping - surreal -- Clip all bands of an aerial tile by a 20 meter buffer. -- Only difference is we don't specify a specific band to clip -- so all bands are clipped SELECT ST_Clip(rast, ST_Buffer(ST_Centroid(ST_Envelope(rast)), 20), false ) from aerials.boston WHERE rid = 4; Full raster tile before clipping After Clipping , , ST_ColorMap Creates a new raster of up to four 8BUI bands (grayscale, RGB, RGBA) from the source raster and a specified band. Band 1 is assumed if not specified. raster ST_ColorMap raster rast integer nband=1 text colormap=grayscale text method=INTERPOLATE raster ST_ColorMap raster rast text colormap text method=INTERPOLATE Apply a colormap to the band at nband of rast resulting a new raster comprised of up to four 8BUI bands. The number of 8BUI bands in the new raster is determined by the number of color components defined in colormap. If nband is not specified, then band 1 is assumed. colormap can be a keyword of a pre-defined colormap or a set of lines defining the value and the color components. Valid pre-defined colormap keyword: grayscale or greyscale for a one 8BUI band raster of shades of gray. pseudocolor for a four 8BUI (RGBA) band raster with colors going from blue to green to red. fire for a four 8BUI (RGBA) band raster with colors going from black to red to pale yellow. bluered for a four 8BUI (RGBA) band raster with colors going from blue to pale white to red. Users can pass a set of entries (one per line) to colormap to specify custom colormaps. Each entry generally consists of five values: the pixel value and corresponding Red, Green, Blue, Alpha components (color components between 0 and 255). Percent values can be used instead of pixel values where 0% and 100% are the minimum and maximum values found in the raster band. Values can be separated with commas (','), tabs, colons (':') and/or spaces. The pixel value can be set to nv, null or nodata for the NODATA value. An example is provided below. 5 0 0 0 255 4 100:50 55 255 1 150,100 150 255 0% 255 255 255 255 nv 0 0 0 0 The syntax of colormap is similar to that of the color-relief mode of GDAL gdaldem. Valid keywords for method: INTERPOLATE to use linear interpolation to smoothly blend the colors between the given pixel values EXACT to strictly match only those pixels values found in the colormap. Pixels whose value does not match a colormap entry will be set to 0 0 0 0 (RGBA) NEAREST to use the colormap entry whose value is closest to the pixel value A great reference for colormaps is ColorBrewer. The resulting bands of new raster will have no NODATA value set. Use to set a NODATA value if one is needed. Availability: 2.1.0 This is a junk table to play with -- setup test raster table -- DROP TABLE IF EXISTS funky_shapes; CREATE TABLE funky_shapes(rast raster); INSERT INTO funky_shapes(rast) WITH ref AS ( SELECT ST_MakeEmptyRaster( 200, 200, 0, 200, 1, -1, 0, 0) AS rast ) SELECT ST_Union(rast) FROM ( SELECT ST_AsRaster( ST_Rotate( ST_Buffer( ST_GeomFromText('LINESTRING(0 2,50 50,150 150,125 50)'), i*2 ), pi() * i * 0.125, ST_Point(50,50) ), ref.rast, '8BUI'::text, i * 5 ) AS rast FROM ref CROSS JOIN generate_series(1, 10, 3) AS i ) AS shapes; SELECT ST_NumBands(rast) As n_orig, ST_NumBands(ST_ColorMap(rast,1, 'greyscale')) As ngrey, ST_NumBands(ST_ColorMap(rast,1, 'pseudocolor')) As npseudo, ST_NumBands(ST_ColorMap(rast,1, 'fire')) As nfire, ST_NumBands(ST_ColorMap(rast,1, 'bluered')) As nbluered, ST_NumBands(ST_ColorMap(rast,1, ' 100% 255 0 0 80% 160 0 0 50% 130 0 0 30% 30 0 0 20% 60 0 0 0% 0 0 0 nv 255 255 255 ')) As nred FROM funky_shapes; n_orig | ngrey | npseudo | nfire | nbluered | nred --------+-------+---------+-------+----------+------ 1 | 1 | 4 | 4 | 4 | 3 SELECT ST_AsPNG(rast) As orig_png, ST_AsPNG(ST_ColorMap(rast,1,'greyscale')) As grey_png, ST_AsPNG(ST_ColorMap(rast,1, 'pseudocolor')) As pseudo_png, ST_AsPNG(ST_ColorMap(rast,1, 'nfire')) As fire_png, ST_AsPNG(ST_ColorMap(rast,1, 'bluered')) As bluered_png, ST_AsPNG(ST_ColorMap(rast,1, ' 100% 255 0 0 80% 160 0 0 50% 130 0 0 30% 30 0 0 20% 60 0 0 0% 0 0 0 nv 255 255 255 ')) As red_png FROM funky_shapes; orig_png grey_png pseudo_png fire_png bluered_png red_png , , , , , ST_Intersection Returns a raster or a set of geometry-pixelvalue pairs representing the shared portion of two rasters or the geometrical intersection of a vectorization of the raster and a geometry. setof geomval ST_Intersection geometry geom raster rast integer band_num=1 setof geomval ST_Intersection raster rast geometry geom setof geomval ST_Intersection raster rast integer band_num geometry geom raster ST_Intersection raster rast1 raster rast2 double precision[] nodataval raster ST_Intersection raster rast1 raster rast2 text returnband='BOTH' double precision[] nodataval=NULL raster ST_Intersection raster rast1 integer band_num1 raster rast2 integer band_num2 double precision[] nodataval raster ST_Intersection raster rast1 integer band_num1 raster rast2 integer band_num2 text returnband='BOTH' double precision[] nodataval=NULL Returns a raster or a set of geometry-pixelvalue pairs representing the shared portion of two rasters or the geometrical intersection of a vectorization of the raster and a geometry. The first three variants, returning a setof geomval, works in vector space. The raster is first vectorized (using ST_DumpAsPolygon) into a set of geomval rows and those rows are then intersected with the geometry using the ST_Intersection(geometry, geometry) PostGIS function. Geometries intersecting only with a nodata value area of a raster returns an empty geometry. They are normally excluded from the results by the proper usage of ST_Intersect in the WHERE clause. You can access the geometry and the value parts of the resulting set of geomval by surrounding them with parenthesis and adding '.geom' or '.val' at the end of the expression. e.g. (ST_Intersection(rast, geom)).geom The other variants, returning a raster, works in raster space. They are using the two rasters version of ST_MapAlgebraExpr to perform the intersection. The extent of the resulting raster corresponds to the geometrical intersection of the two raster extents. The resulting raster includes 'BAND1', 'BAND2' or 'BOTH' bands, following what is passed as the returnband parameter. Nodata value areas present in any band results in nodata value areas in every bands of the result. In other words, any pixel intersecting with a nodata value pixel becomes a nodata value pixel in the result. Rasters resulting from ST_Intersection must have a nodata value assigned for areas not intersecting. You can define or replace the nodata value for any resulting band by providing a nodataval[] array of one or two nodata values depending if you request 'BAND1', 'BAND2' or 'BOTH' bands. The first value in the array replace the nodata value in the first band and the second value replace the nodata value in the second band. If one input band do not have a nodata value defined and none are provided as an array, one is chosen using the ST_MinPossibleValue function. All variant accepting an array of nodata value can also accept a single value which will be assigned to each requested band. In all variants, if no band number is specified band 1 is assumed. To get more control on the resulting extent or on what to return when encountering a nodata value, use the two rasters version of . To compute the intersection of a raster band with a geometry in raster space, use . ST_Clip works on multiple bands rasters and does not return a band corresponding to the rasterized geometry. ST_Intersection should be used in conjunction with ST_Intersects and an index on the raster column and/or the geometry column. Enhanced: 2.0.0 - Intersection in the raster space was introduced. In earlier pre-2.0.0 versions, only intersection performed in vector space were supported. SELECT foo.rid, foo.gid, ST_AsText((foo.geomval).geom) As geomwkt, (foo.geomval).val FROM ( SELECT A.rid, g.gid, ST_Intersection(A.rast, g.geom) As geomval FROM dummy_rast AS A CROSS JOIN ( VALUES (1, ST_Point(3427928, 5793243.85) ), (2, ST_GeomFromText('LINESTRING(3427927.85 5793243.75,3427927.8 5793243.75,3427927.8 5793243.8)')), (3, ST_GeomFromText('LINESTRING(1 2, 3 4)')) ) As g(gid,geom) WHERE A.rid = 2 ) As foo; rid | gid | geomwkt | val -----+-----+--------------------------------------------------------------------------------------------- 2 | 1 | POINT(3427928 5793243.85) | 249 2 | 1 | POINT(3427928 5793243.85) | 253 2 | 2 | POINT(3427927.85 5793243.75) | 254 2 | 2 | POINT(3427927.8 5793243.8) | 251 2 | 2 | POINT(3427927.8 5793243.8) | 253 2 | 2 | LINESTRING(3427927.8 5793243.75,3427927.8 5793243.8) | 252 2 | 2 | MULTILINESTRING((3427927.8 5793243.8,3427927.8 5793243.75),...) | 250 2 | 3 | GEOMETRYCOLLECTION EMPTY Examples coming soon , , , , ST_MapAlgebra Callback function version - Returns a one-band raster given one or more input rasters, band indexes and one user-specified callback function. raster ST_MapAlgebra rastbandarg[] rastbandargset regprocedure callbackfunc text pixeltype=NULL text extenttype=INTERSECTION raster customextent=NULL integer distancex=0 integer distancey=0 text[] VARIADIC userargs=NULL raster ST_MapAlgebra raster rast integer[] nband regprocedure callbackfunc text pixeltype=NULL text extenttype=FIRST raster customextent=NULL integer distancex=0 integer distancey=0 text[] VARIADIC userargs=NULL raster ST_MapAlgebra raster rast integer nband regprocedure callbackfunc text pixeltype=NULL text extenttype=FIRST raster customextent=NULL integer distancex=0 integer distancey=0 text[] VARIADIC userargs=NULL raster ST_MapAlgebra raster rast1 integer nband1 raster rast2 integer nband2 regprocedure callbackfunc text pixeltype=NULL text extenttype=INTERSECTION raster customextent=NULL integer distancex=0 integer distancey=0 text[] VARIADIC userargs=NULL Returns a one-band raster given one or more input rasters, band indexes and one user-specified callback function. rast,rast1,rast2, rastbandargset Rasters on which the map algebra process is evaluated.rastbandargset allows the use of a map algebra operation on many rasters and/or many bands. See example Variant 1. nband, nband1, nband2 Band numbers of the raster to be evaluated. nband can be an integer or integer[] denoting the bands. nband1 is band on rast1 and nband2 is band on rast2 for hte 2 raster/2band case. callbackfunc The callbackfunc parameter must be the name and signature of an SQL or PL/pgSQL function, cast to a regprocedure. An example PL/pgSQL function example is: CREATE OR REPLACE FUNCTION sample_callbackfunc(value double precision[][][], position integer[][], VARIADIC userargs text[]) RETURNS double precision AS $$ BEGIN RETURN 0; END; $$ LANGUAGE 'plpgsql' IMMUTABLE; The callbackfunc must have three arguments: a 3-dimension double precision array, a 2-dimension integer array and a variadic 1-dimension text array. The first argument value is the set of values (as double precision) from all input rasters. The three dimensions (where indexes are 1-based) are: raster #, row y, column x. The second argument position is the set of pixel positions from the output raster and input rasters. The outer dimension (where indexes are 0-based) is the raster #. The position at outer dimension index 0 is the output raster's pixel position. For each outer dimension, there are two elements in the inner dimension for X and Y. The third argument userargs is for passing through any user-specified arguments. Passing a regprocedure argument to a SQL function requires the full function signature to be passed, then cast to a regprocedure type. To pass the above example PL/pgSQL function as an argument, the SQL for the argument is: 'sample_callbackfunc(double precision[], integer[], text[])'::regprocedure Note that the argument contains the name of the function, the types of the function arguments, quotes around the name and argument types, and a cast to a regprocedure. pixeltype If pixeltype is passed in, the one band of the new raster will be of that pixeltype. If pixeltype is passed NULL or left out, the new raster band will have the same pixeltype as the specified band of the first raster (for extent types: INTERSECTION, UNION, FIRST, CUSTOM) or the specified band of the appropriate raster (for extent types: SECOND, LAST). If in doubt, always specify pixeltype. The resulting pixel type of the output raster must be one listed in or left out or set to NULL. extenttype Possible values are INTERSECTION (default), UNION, FIRST (default for one raster variants), SECOND, LAST, CUSTOM. customextent If extentype is CUSTOM, a raster must be provided for customextent. See example 4 of Variant 1. distancex The distance in pixels from the reference cell. So width of resulting matrix would be 2*distancex + 1.If not specified only the reference cell is considered (neighborhood of 0). distancey The distance in pixels from reference cell in y direction. Height of resulting matrix would be 2*distancey + 1 .If not specified only the reference cell is considered (neighborhood of 0). userargs The third argument to the callbackfunc is a variadic text array. All trailing text arguments are passed through to the specified callbackfunc, and are contained in the userargs argument. For more information about the VARIADIC keyword, please refer to the PostgreSQL documentation and the "SQL Functions with Variable Numbers of Arguments" section of Query Language (SQL) Functions. The text[] argument to the callbackfunc is required, regardless of whether you choose to pass any arguments to the callback function for processing or not. Variant 1 accepts an array of rastbandarg allowing the use of a map algebra operation on many rasters and/or many bands. See example Variant 1. Variants 2 and 3 operate upon one or more bands of one raster. See example Variant 2 and 3. Variant 4 operate upon two rasters with one band per raster. See example Variant 4. Availability: 2.1.0 One raster, one band WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0) AS rast ) SELECT ST_MapAlgebra( ARRAY[ROW(rast, 1)]::rastbandarg[], 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo One raster, several bands WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast ) SELECT ST_MapAlgebra( ARRAY[ROW(rast, 3), ROW(rast, 1), ROW(rast, 3), ROW(rast, 2)]::rastbandarg[], 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo Several rasters, several bands WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast UNION ALL SELECT 2 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 1, 1, -1, 0, 0, 0), 1, '16BUI', 2, 0), 2, '8BUI', 20, 0), 3, '32BUI', 300, 0) AS rast ) SELECT ST_MapAlgebra( ARRAY[ROW(t1.rast, 3), ROW(t2.rast, 1), ROW(t2.rast, 3), ROW(t1.rast, 2)]::rastbandarg[], 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo t1 CROSS JOIN foo t2 WHERE t1.rid = 1 AND t2.rid = 2 Complete example of tiles of a coverage with neighborhood. This query only works with PostgreSQL 9.1 or higher. WITH foo AS ( SELECT 0 AS rid, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0) AS rast UNION ALL SELECT 1, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, 0, 1, -1, 0, 0, 0), 1, '16BUI', 2, 0) AS rast UNION ALL SELECT 2, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, 0, 1, -1, 0, 0, 0), 1, '16BUI', 3, 0) AS rast UNION ALL SELECT 3, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, -2, 1, -1, 0, 0, 0), 1, '16BUI', 10, 0) AS rast UNION ALL SELECT 4, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, -2, 1, -1, 0, 0, 0), 1, '16BUI', 20, 0) AS rast UNION ALL SELECT 5, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, -2, 1, -1, 0, 0, 0), 1, '16BUI', 30, 0) AS rast UNION ALL SELECT 6, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, -4, 1, -1, 0, 0, 0), 1, '16BUI', 100, 0) AS rast UNION ALL SELECT 7, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, -4, 1, -1, 0, 0, 0), 1, '16BUI', 200, 0) AS rast UNION ALL SELECT 8, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, -4, 1, -1, 0, 0, 0), 1, '16BUI', 300, 0) AS rast ) SELECT t1.rid, ST_MapAlgebra( ARRAY[ROW(ST_Union(t2.rast), 1)]::rastbandarg[], 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure, '32BUI', 'CUSTOM', t1.rast, 1, 1 ) AS rast FROM foo t1 CROSS JOIN foo t2 WHERE t1.rid = 4 AND t2.rid BETWEEN 0 AND 8 AND ST_Intersects(t1.rast, t2.rast) GROUP BY t1.rid, t1.rast Example like the prior one for tiles of a coverage with neighborhood but works with PostgreSQL 9.0. WITH src AS ( SELECT 0 AS rid, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0) AS rast UNION ALL SELECT 1, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, 0, 1, -1, 0, 0, 0), 1, '16BUI', 2, 0) AS rast UNION ALL SELECT 2, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, 0, 1, -1, 0, 0, 0), 1, '16BUI', 3, 0) AS rast UNION ALL SELECT 3, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, -2, 1, -1, 0, 0, 0), 1, '16BUI', 10, 0) AS rast UNION ALL SELECT 4, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, -2, 1, -1, 0, 0, 0), 1, '16BUI', 20, 0) AS rast UNION ALL SELECT 5, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, -2, 1, -1, 0, 0, 0), 1, '16BUI', 30, 0) AS rast UNION ALL SELECT 6, ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, -4, 1, -1, 0, 0, 0), 1, '16BUI', 100, 0) AS rast UNION ALL SELECT 7, ST_AddBand(ST_MakeEmptyRaster(2, 2, 2, -4, 1, -1, 0, 0, 0), 1, '16BUI', 200, 0) AS rast UNION ALL SELECT 8, ST_AddBand(ST_MakeEmptyRaster(2, 2, 4, -4, 1, -1, 0, 0, 0), 1, '16BUI', 300, 0) AS rast ) WITH foo AS ( SELECT t1.rid, ST_Union(t2.rast) AS rast FROM src t1 JOIN src t2 ON ST_Intersects(t1.rast, t2.rast) AND t2.rid BETWEEN 0 AND 8 WHERE t1.rid = 4 GROUP BY t1.rid ), bar AS ( SELECT t1.rid, ST_MapAlgebra( ARRAY[ROW(t2.rast, 1)]::rastbandarg[], 'raster_nmapalgebra_test(double precision[], int[], text[])'::regprocedure, '32BUI', 'CUSTOM', t1.rast, 1, 1 ) AS rast FROM src t1 JOIN foo t2 ON t1.rid = t2.rid ) SELECT rid, (ST_Metadata(rast)), (ST_BandMetadata(rast, 1)), ST_Value(rast, 1, 1, 1) FROM bar; One raster, several bands WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast ) SELECT ST_MapAlgebra( rast, ARRAY[3, 1, 3, 2]::integer[], 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo One raster, one band WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast ) SELECT ST_MapAlgebra( rast, 2, 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo Two rasters, two bands WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast UNION ALL SELECT 2 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 1, 1, -1, 0, 0, 0), 1, '16BUI', 2, 0), 2, '8BUI', 20, 0), 3, '32BUI', 300, 0) AS rast ) SELECT ST_MapAlgebra( t1.rast, 2, t2.rast, 1, 'sample_callbackfunc(double precision[], int[], text[])'::regprocedure ) AS rast FROM foo t1 CROSS JOIN foo t2 WHERE t1.rid = 1 AND t2.rid = 2 , , ST_MapAlgebra Expression version - Returns a one-band raster given one or two input rasters, band indexes and one or more user-specified SQL expressions. raster ST_MapAlgebra raster rast integer nband text pixeltype text expression double precision nodataval=NULL raster ST_MapAlgebra raster rast text pixeltype text expression double precision nodataval=NULL raster ST_MapAlgebra raster rast1 integer nband1 raster rast2 integer nband2 text expression text pixeltype=NULL text extenttype=INTERSECTION text nodata1expr=NULL text nodata2expr=NULL double precision nodatanodataval=NULL raster ST_MapAlgebra raster rast1 raster rast2 text expression text pixeltype=NULL text extenttype=INTERSECTION text nodata1expr=NULL text nodata2expr=NULL double precision nodatanodataval=NULL Expression version - Returns a one-band raster given one or two input rasters, band indexes and one or more user-specified SQL expressions. Availability: 2.1.0 Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation defined by the expression on the input raster (rast). If nband is not provided, band 1 is assumed. The new raster will have the same georeference, width, and height as the original raster but will only have one band. If pixeltype is passed in, then the new raster will have a band of that pixeltype. If pixeltype is passed NULL, then the new raster band will have the same pixeltype as the input rast band. Keywords permitted for expression [rast] - Pixel value of the pixel of interest [rast.val] - Pixel value of the pixel of interest [rast.x] - 1-based pixel column of the pixel of interest [rast.y] - 1-based pixel row of the pixel of interest Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation to the two bands defined by the expression on the two input raster bands rast1, (rast2). If no band1, band2 is specified band 1 is assumed. The resulting raster will be aligned (scale, skew and pixel corners) on the grid defined by the first raster. The resulting raster will have the extent defined by the extenttype parameter. expression A PostgreSQL algebraic expression involving the two rasters and PostgreSQL defined functions/operators that will define the pixel value when pixels intersect. e.g. (([rast1] + [rast2])/2.0)::integer pixeltype The resulting pixel type of the output raster. Must be one listed in , left out or set to NULL. If not passed in or set to NULL, will default to the pixeltype of the first raster. extenttype Controls the extent of resulting raster INTERSECTION - The extent of the new raster is the intersection of the two rasters. This is the default. UNION - The extent of the new raster is the union of the two rasters. FIRST - The extent of the new raster is the same as the one of the first raster. SECOND - The extent of the new raster is the same as the one of the second raster. nodata1expr An algebraic expression involving only rast2 or a constant that defines what to return when pixels of rast1 are nodata values and spatially corresponding rast2 pixels have values. nodata2expr An algebraic expression involving only rast1 or a constant that defines what to return when pixels of rast2 are nodata values and spatially corresponding rast1 pixels have values. nodatanodataval A numeric constant to return when spatially corresponding rast1 and rast2 pixels are both nodata values. Keywords permitted in expression, nodata1expr and nodata2expr [rast1] - Pixel value of the pixel of interest from rast1 [rast1.val] - Pixel value of the pixel of interest from rast1 [rast1.x] - 1-based pixel column of the pixel of interest from rast1 [rast1.y] - 1-based pixel row of the pixel of interest from rast1 [rast2] - Pixel value of the pixel of interest from rast2 [rast2.val] - Pixel value of the pixel of interest from rast2 [rast2.x] - 1-based pixel column of the pixel of interest from rast2 [rast2.y] - 1-based pixel row of the pixel of interest from rast2 WITH foo AS ( SELECT ST_AddBand(ST_MakeEmptyRaster(10, 10, 0, 0, 1, 1, 0, 0, 0), '32BF', 1, -1) AS rast ) SELECT ST_MapAlgebra(rast, 1, NULL, 'ceil([rast]*[rast.x]/[rast.y]+[rast.val])') FROM foo WITH foo AS ( SELECT 1 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 1, -1, 0, 0, 0), 1, '16BUI', 1, 0), 2, '8BUI', 10, 0), 3, '32BUI', 100, 0) AS rast UNION ALL SELECT 2 AS rid, ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 1, 1, -1, 0, 0, 0), 1, '16BUI', 2, 0), 2, '8BUI', 20, 0), 3, '32BUI', 300, 0) AS rast ) SELECT ST_MapAlgebra( t1.rast, 2, t2.rast, 1, '([rast2] + [rast1.val]) / 2' ) AS rast FROM foo t1 CROSS JOIN foo t2 WHERE t1.rid = 1 AND t2.rid = 2 , , ST_MapAlgebraExpr 1 raster band version: Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation on the input raster band and of pixeltype provided. Band 1 is assumed if no band is specified. raster ST_MapAlgebraExpr raster rast integer band text pixeltype text expression double precision nodataval=NULL raster ST_MapAlgebraExpr raster rast text pixeltype text expression double precision nodataval=NULL is deprecated as of 2.1.0. Use instead. Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation defined by the expression on the input raster (rast). If no band is specified band 1 is assumed. The new raster will have the same georeference, width, and height as the original raster but will only have one band. If pixeltype is passed in, then the new raster will have a band of that pixeltype. If pixeltype is passed NULL, then the new raster band will have the same pixeltype as the input rast band. In the expression you can use the term [rast] to refer to the pixel value of the original band, [rast.x] to refer to the 1-based pixel column index, [rast.y] to refer to the 1-based pixel row index. Availability: 2.0.0 Create a new 1 band raster from our original that is a function of modulo 2 of the original raster band. ALTER TABLE dummy_rast ADD COLUMN map_rast raster; UPDATE dummy_rast SET map_rast = ST_MapAlgebraExpr(rast,NULL,'mod([rast],2)') WHERE rid = 2; SELECT ST_Value(rast,1,i,j) As origval, ST_Value(map_rast, 1, i, j) As mapval FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j WHERE rid = 2; origval | mapval ---------+-------- 253 | 1 254 | 0 253 | 1 253 | 1 254 | 0 254 | 0 250 | 0 254 | 0 254 | 0 Create a new 1 band raster of pixel-type 2BUI from our original that is reclassified and set the nodata value to be 0. ALTER TABLE dummy_rast ADD COLUMN map_rast2 raster; UPDATE dummy_rast SET map_rast2 = ST_MapAlgebraExpr(rast,'2BUI','CASE WHEN [rast] BETWEEN 100 and 250 THEN 1 WHEN [rast] = 252 THEN 2 WHEN [rast] BETWEEN 253 and 254 THEN 3 ELSE 0 END', '0') WHERE rid = 2; SELECT DISTINCT ST_Value(rast,1,i,j) As origval, ST_Value(map_rast2, 1, i, j) As mapval FROM dummy_rast CROSS JOIN generate_series(1, 5) AS i CROSS JOIN generate_series(1,5) AS j WHERE rid = 2; origval | mapval ---------+-------- 249 | 1 250 | 1 251 | 252 | 2 253 | 3 254 | 3 SELECT ST_BandPixelType(map_rast2) As b1pixtyp FROM dummy_rast WHERE rid = 2; b1pixtyp ---------- 2BUI original (column rast-view) rast_view_ma Create a new 3 band raster same pixel type from our original 3 band raster with first band altered by map algebra and remaining 2 bands unaltered. SELECT ST_AddBand( ST_AddBand( ST_AddBand( ST_MakeEmptyRaster(rast_view), ST_MapAlgebraExpr(rast_view,1,NULL,'tan([rast])*[rast]') ), ST_Band(rast_view,2) ), ST_Band(rast_view, 3) As rast_view_ma ) FROM wind WHERE rid=167; , , , , ST_MapAlgebraExpr 2 raster band version: Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation on the two input raster bands and of pixeltype provided. band 1 of each raster is assumed if no band numbers are specified. The resulting raster will be aligned (scale, skew and pixel corners) on the grid defined by the first raster and have its extent defined by the "extenttype" parameter. Values for "extenttype" can be: INTERSECTION, UNION, FIRST, SECOND. raster ST_MapAlgebraExpr raster rast1 raster rast2 text expression text pixeltype=same_as_rast1_band text extenttype=INTERSECTION text nodata1expr=NULL text nodata2expr=NULL double precision nodatanodataval=NULL raster ST_MapAlgebraExpr raster rast1 integer band1 raster rast2 integer band2 text expression text pixeltype=same_as_rast1_band text extenttype=INTERSECTION text nodata1expr=NULL text nodata2expr=NULL double precision nodatanodataval=NULL is deprecated as of 2.1.0. Use instead. Creates a new one band raster formed by applying a valid PostgreSQL algebraic operation to the two bands defined by the expression on the two input raster bands rast1, (rast2). If no band1, band2 is specified band 1 is assumed. The resulting raster will be aligned (scale, skew and pixel corners) on the grid defined by the first raster. The resulting raster will have the extent defined by the extenttype parameter. expression A PostgreSQL algebraic expression involving the two rasters and PostgreSQL defined functions/operators that will define the pixel value when pixels intersect. e.g. (([rast1] + [rast2])/2.0)::integer pixeltype The resulting pixel type of the output raster. Must be one listed in , left out or set to NULL. If not passed in or set to NULL, will default to the pixeltype of the first raster. extenttype Controls the extent of resulting raster INTERSECTION - The extent of the new raster is the intersection of the two rasters. This is the default. UNION - The extent of the new raster is the union of the two rasters. FIRST - The extent of the new raster is the same as the one of the first raster. SECOND - The extent of the new raster is the same as the one of the second raster. nodata1expr An algebraic expression involving only rast2 or a constant that defines what to return when pixels of rast1 are nodata values and spatially corresponding rast2 pixels have values. nodata2expr An algebraic expression involving only rast1 or a constant that defines what to return when pixels of rast2 are nodata values and spatially corresponding rast1 pixels have values. nodatanodataval A numeric constant to return when spatially corresponding rast1 and rast2 pixels are both nodata values. If pixeltype is passed in, then the new raster will have a band of that pixeltype. If pixeltype is passed NULL or no pixel type specified, then the new raster band will have the same pixeltype as the input rast1 band. Use the term [rast1.val] [rast2.val] to refer to the pixel value of the original raster bands and [rast1.x], [rast1.y] etc. to refer to the column / row positions of the pixels. Availability: 2.0.0 Create a new 1 band raster from our original that is a function of modulo 2 of the original raster band. --Create a cool set of rasters -- DROP TABLE IF EXISTS fun_shapes; CREATE TABLE fun_shapes(rid serial PRIMARY KEY, fun_name text, rast raster); -- Insert some cool shapes around Boston in Massachusetts state plane meters -- INSERT INTO fun_shapes(fun_name, rast) VALUES ('ref', ST_AsRaster(ST_MakeEnvelope(235229, 899970, 237229, 901930,26986),200,200,'8BUI',0,0)); INSERT INTO fun_shapes(fun_name,rast) WITH ref(rast) AS (SELECT rast FROM fun_shapes WHERE fun_name = 'ref' ) SELECT 'area' AS fun_name, ST_AsRaster(ST_Buffer(ST_SetSRID(ST_Point(236229, 900930),26986), 1000), ref.rast,'8BUI', 10, 0) As rast FROM ref UNION ALL SELECT 'rand bubbles', ST_AsRaster( (SELECT ST_Collect(geom) FROM (SELECT ST_Buffer(ST_SetSRID(ST_Point(236229 + i*random()*100, 900930 + j*random()*100),26986), random()*20) As geom FROM generate_series(1,10) As i, generate_series(1,10) As j ) As foo ), ref.rast,'8BUI', 200, 0) FROM ref; --map them - SELECT ST_MapAlgebraExpr( area.rast, bub.rast, '[rast2.val]', '8BUI', 'INTERSECTION', '[rast2.val]', '[rast1.val]') As interrast, ST_MapAlgebraExpr( area.rast, bub.rast, '[rast2.val]', '8BUI', 'UNION', '[rast2.val]', '[rast1.val]') As unionrast FROM (SELECT rast FROM fun_shapes WHERE fun_name = 'area') As area CROSS JOIN (SELECT rast FROM fun_shapes WHERE fun_name = 'rand bubbles') As bub mapalgebra intersection map algebra union -- we use ST_AsPNG to render the image so all single band ones look grey -- WITH mygeoms AS ( SELECT 2 As bnum, ST_Buffer(ST_Point(1,5),10) As geom UNION ALL SELECT 3 AS bnum, ST_Buffer(ST_GeomFromText('LINESTRING(50 50,150 150,150 50)'), 10,'join=bevel') As geom UNION ALL SELECT 1 As bnum, ST_Buffer(ST_GeomFromText('LINESTRING(60 50,150 150,150 50)'), 5,'join=bevel') As geom ), -- define our canvas to be 1 to 1 pixel to geometry canvas AS (SELECT ST_AddBand(ST_MakeEmptyRaster(200, 200, ST_XMin(e)::integer, ST_YMax(e)::integer, 1, -1, 0, 0) , '8BUI'::text,0) As rast FROM (SELECT ST_Extent(geom) As e, Max(ST_SRID(geom)) As srid from mygeoms ) As foo ), rbands AS (SELECT ARRAY(SELECT ST_MapAlgebraExpr(canvas.rast, ST_AsRaster(m.geom, canvas.rast, '8BUI', 100), '[rast2.val]', '8BUI', 'FIRST', '[rast2.val]', '[rast1.val]') As rast FROM mygeoms AS m CROSS JOIN canvas ORDER BY m.bnum) As rasts ) SELECT rasts[1] As rast1 , rasts[2] As rast2, rasts[3] As rast3, ST_AddBand( ST_AddBand(rasts[1],rasts[2]), rasts[3]) As final_rast FROM rbands; rast1 rast2 rast3 final_rast -- Create new 3 band raster composed of first 2 clipped bands, and overlay of 3rd band with our geometry -- This query took 3.6 seconds on PostGIS windows 64-bit install WITH pr AS -- Note the order of operation: we clip all the rasters to dimensions of our region (SELECT ST_Clip(rast,ST_Expand(geom,50) ) As rast, g.geom FROM aerials.o_2_boston AS r INNER JOIN -- union our parcels of interest so they form a single geometry we can later intersect with (SELECT ST_Union(ST_Transform(the_geom,26986)) AS geom FROM landparcels WHERE pid IN('0303890000', '0303900000')) As g ON ST_Intersects(rast::geometry, ST_Expand(g.geom,50)) ), -- we then union the raster shards together -- ST_Union on raster is kinda of slow but much faster the smaller you can get the rasters -- therefore we want to clip first and then union prunion AS (SELECT ST_AddBand(NULL, ARRAY[ST_Union(rast,1),ST_Union(rast,2),ST_Union(rast,3)] ) As clipped,geom FROM pr GROUP BY geom) -- return our final raster which is the unioned shard with -- with the overlay of our parcel boundaries -- add first 2 bands, then mapalgebra of 3rd band + geometry SELECT ST_AddBand(ST_Band(clipped,ARRAY[1,2]) , ST_MapAlgebraExpr(ST_Band(clipped,3), ST_AsRaster(ST_Buffer(ST_Boundary(geom),2),clipped, '8BUI',250), '[rast2.val]', '8BUI', 'FIRST', '[rast2.val]', '[rast1.val]') ) As rast FROM prunion; The blue lines are the boundaries of select parcels , , , , , , , , , ST_MapAlgebraFct 1 band version - Creates a new one band raster formed by applying a valid PostgreSQL function on the input raster band and of pixeltype prodived. Band 1 is assumed if no band is specified. raster ST_MapAlgebraFct raster rast regprocedure onerasteruserfunc raster ST_MapAlgebraFct raster rast regprocedure onerasteruserfunc text[] VARIADIC args raster ST_MapAlgebraFct raster rast text pixeltype regprocedure onerasteruserfunc raster ST_MapAlgebraFct raster rast text pixeltype regprocedure onerasteruserfunc text[] VARIADIC args raster ST_MapAlgebraFct raster rast integer band regprocedure onerasteruserfunc raster ST_MapAlgebraFct raster rast integer band regprocedure onerasteruserfunc text[] VARIADIC args raster ST_MapAlgebraFct raster rast integer band text pixeltype regprocedure onerasteruserfunc raster ST_MapAlgebraFct raster rast integer band text pixeltype regprocedure onerasteruserfunc text[] VARIADIC args is deprecated as of 2.1.0. Use instead. Creates a new one band raster formed by applying a valid PostgreSQL function specified by the onerasteruserfunc on the input raster (rast). If no band is specified, band 1 is assumed. The new raster will have the same georeference, width, and height as the original raster but will only have one band. If pixeltype is passed in, then the new raster will have a band of that pixeltype. If pixeltype is passed NULL, then the new raster band will have the same pixeltype as the input rast band. The onerasteruserfunc parameter must be the name and signature of a SQL or PL/pgSQL function, cast to a regprocedure. A very simple and quite useless PL/pgSQL function example is: CREATE OR REPLACE FUNCTION simple_function(pixel FLOAT, pos INTEGER[], VARIADIC args TEXT[]) RETURNS FLOAT AS $$ BEGIN RETURN 0.0; END; $$ LANGUAGE 'plpgsql' IMMUTABLE; The userfunction may accept two or three arguments: a float value, an optional integer array, and a variadic text array. The first argument is the value of an individual raster cell (regardless of the raster datatype). The second argument is the position of the current processing cell in the form '{x,y}'. The third argument indicates that all remaining parameters to shall be passed through to the userfunction. Passing a regprodedure argument to a SQL function requires the full function signature to be passed, then cast to a regprocedure type. To pass the above example PL/pgSQL function as an argument, the SQL for the argument is:'simple_function(float,integer[],text[])'::regprocedureNote that the argument contains the name of the function, the types of the function arguments, quotes around the name and argument types, and a cast to a regprocedure. The third argument to the userfunction is a variadic text array. All trailing text arguments to any call are passed through to the specified userfunction, and are contained in the args argument. For more information about the VARIADIC keyword, please refer to the PostgreSQL documentation and the "SQL Functions with Variable Numbers of Arguments" section of Query Language (SQL) Functions. The text[] argument to the userfunction is required, regardless of whether you choose to pass any arguments to your user function for processing or not. Availability: 2.0.0 Create a new 1 band raster from our original that is a function of modulo 2 of the original raster band. ALTER TABLE dummy_rast ADD COLUMN map_rast raster; CREATE FUNCTION mod_fct(pixel float, pos integer[], variadic args text[]) RETURNS float AS $$ BEGIN RETURN pixel::integer % 2; END; $$ LANGUAGE 'plpgsql' IMMUTABLE; UPDATE dummy_rast SET map_rast = ST_MapAlgebraFct(rast,NULL,'mod_fct(float,integer[],text[])'::regprocedure) WHERE rid = 2; SELECT ST_Value(rast,1,i,j) As origval, ST_Value(map_rast, 1, i, j) As mapval FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j WHERE rid = 2; origval | mapval ---------+-------- 253 | 1 254 | 0 253 | 1 253 | 1 254 | 0 254 | 0 250 | 0 254 | 0 254 | 0 Create a new 1 band raster of pixel-type 2BUI from our original that is reclassified and set the nodata value to a passed parameter to the user function (0). ALTER TABLE dummy_rast ADD COLUMN map_rast2 raster; CREATE FUNCTION classify_fct(pixel float, pos integer[], variadic args text[]) RETURNS float AS $$ DECLARE nodata float := 0; BEGIN IF NOT args[1] IS NULL THEN nodata := args[1]; END IF; IF pixel < 251 THEN RETURN 1; ELSIF pixel = 252 THEN RETURN 2; ELSIF pixel > 252 THEN RETURN 3; ELSE RETURN nodata; END IF; END; $$ LANGUAGE 'plpgsql'; UPDATE dummy_rast SET map_rast2 = ST_MapAlgebraFct(rast,'2BUI','classify_fct(float,integer[],text[])'::regprocedure, '0') WHERE rid = 2; SELECT DISTINCT ST_Value(rast,1,i,j) As origval, ST_Value(map_rast2, 1, i, j) As mapval FROM dummy_rast CROSS JOIN generate_series(1, 5) AS i CROSS JOIN generate_series(1,5) AS j WHERE rid = 2; origval | mapval ---------+-------- 249 | 1 250 | 1 251 | 252 | 2 253 | 3 254 | 3 SELECT ST_BandPixelType(map_rast2) As b1pixtyp FROM dummy_rast WHERE rid = 2; b1pixtyp ---------- 2BUI original (column rast-view) rast_view_ma Create a new 3 band raster same pixel type from our original 3 band raster with first band altered by map algebra and remaining 2 bands unaltered. CREATE FUNCTION rast_plus_tan(pixel float, pos integer[], variadic args text[]) RETURNS float AS $$ BEGIN RETURN tan(pixel) * pixel; END; $$ LANGUAGE 'plpgsql'; SELECT ST_AddBand( ST_AddBand( ST_AddBand( ST_MakeEmptyRaster(rast_view), ST_MapAlgebraFct(rast_view,1,NULL,'rast_plus_tan(float,integer[],text[])'::regprocedure) ), ST_Band(rast_view,2) ), ST_Band(rast_view, 3) As rast_view_ma ) FROM wind WHERE rid=167; , , , ST_MapAlgebraFct 2 band version - Creates a new one band raster formed by applying a valid PostgreSQL function on the 2 input raster bands and of pixeltype prodived. Band 1 is assumed if no band is specified. Extent type defaults to INTERSECTION if not specified. raster ST_MapAlgebraFct raster rast1 raster rast2 regprocedure tworastuserfunc text pixeltype=same_as_rast1 text extenttype=INTERSECTION text[] VARIADIC userargs raster ST_MapAlgebraFct raster rast1 integer band1 raster rast2 integer band2 regprocedure tworastuserfunc text pixeltype=same_as_rast1 text extenttype=INTERSECTION text[] VARIADIC userargs is deprecated as of 2.1.0. Use instead. Creates a new one band raster formed by applying a valid PostgreSQL function specified by the tworastuserfunc on the input raster rast1, rast2. If no band1 or band2 is specified, band 1 is assumed. The new raster will have the same georeference, width, and height as the original rasters but will only have one band. If pixeltype is passed in, then the new raster will have a band of that pixeltype. If pixeltype is passed NULL or left out, then the new raster band will have the same pixeltype as the input rast1 band. The tworastuserfunc parameter must be the name and signature of an SQL or PL/pgSQL function, cast to a regprocedure. An example PL/pgSQL function example is: CREATE OR REPLACE FUNCTION simple_function_for_two_rasters(pixel1 FLOAT, pixel2 FLOAT, pos INTEGER[], VARIADIC args TEXT[]) RETURNS FLOAT AS $$ BEGIN RETURN 0.0; END; $$ LANGUAGE 'plpgsql' IMMUTABLE; The tworastuserfunc may accept three or four arguments: a double precision value, a double precision value, an optional integer array, and a variadic text array. The first argument is the value of an individual raster cell in rast1 (regardless of the raster datatype). The second argument is an individual raster cell value in rast2. The third argument is the position of the current processing cell in the form '{x,y}'. The fourth argument indicates that all remaining parameters to shall be passed through to the tworastuserfunc. Passing a regprodedure argument to a SQL function requires the full function signature to be passed, then cast to a regprocedure type. To pass the above example PL/pgSQL function as an argument, the SQL for the argument is:'simple_function(double precision, double precision, integer[], text[])'::regprocedureNote that the argument contains the name of the function, the types of the function arguments, quotes around the name and argument types, and a cast to a regprocedure. The third argument to the tworastuserfunc is a variadic text array. All trailing text arguments to any call are passed through to the specified tworastuserfunc, and are contained in the userargs argument. For more information about the VARIADIC keyword, please refer to the PostgreSQL documentation and the "SQL Functions with Variable Numbers of Arguments" section of Query Language (SQL) Functions. The text[] argument to the tworastuserfunc is required, regardless of whether you choose to pass any arguments to your user function for processing or not. Availability: 2.0.0 -- define our user defined function -- CREATE OR REPLACE FUNCTION raster_mapalgebra_union( rast1 double precision, rast2 double precision, pos integer[], VARIADIC userargs text[] ) RETURNS double precision AS $$ DECLARE BEGIN CASE WHEN rast1 IS NOT NULL AND rast2 IS NOT NULL THEN RETURN ((rast1 + rast2)/2.); WHEN rast1 IS NULL AND rast2 IS NULL THEN RETURN NULL; WHEN rast1 IS NULL THEN RETURN rast2; ELSE RETURN rast1; END CASE; RETURN NULL; END; $$ LANGUAGE 'plpgsql' IMMUTABLE COST 1000; -- prep our test table of rasters DROP TABLE IF EXISTS map_shapes; CREATE TABLE map_shapes(rid serial PRIMARY KEY, rast raster, bnum integer, descrip text); INSERT INTO map_shapes(rast,bnum, descrip) WITH mygeoms AS ( SELECT 2 As bnum, ST_Buffer(ST_Point(90,90),30) As geom, 'circle' As descrip UNION ALL SELECT 3 AS bnum, ST_Buffer(ST_GeomFromText('LINESTRING(50 50,150 150,150 50)'), 15) As geom, 'big road' As descrip UNION ALL SELECT 1 As bnum, ST_Translate(ST_Buffer(ST_GeomFromText('LINESTRING(60 50,150 150,150 50)'), 8,'join=bevel'), 10,-6) As geom, 'small road' As descrip ), -- define our canvas to be 1 to 1 pixel to geometry canvas AS ( SELECT ST_AddBand(ST_MakeEmptyRaster(250, 250, ST_XMin(e)::integer, ST_YMax(e)::integer, 1, -1, 0, 0 ) , '8BUI'::text,0) As rast FROM (SELECT ST_Extent(geom) As e, Max(ST_SRID(geom)) As srid from mygeoms ) As foo ) -- return our rasters aligned with our canvas SELECT ST_AsRaster(m.geom, canvas.rast, '8BUI', 240) As rast, bnum, descrip FROM mygeoms AS m CROSS JOIN canvas UNION ALL SELECT canvas.rast, 4, 'canvas' FROM canvas; -- Map algebra on single band rasters and then collect with ST_AddBand INSERT INTO map_shapes(rast,bnum,descrip) SELECT ST_AddBand(ST_AddBand(rasts[1], rasts[2]),rasts[3]), 4, 'map bands overlay fct union (canvas)' FROM (SELECT ARRAY(SELECT ST_MapAlgebraFct(m1.rast, m2.rast, 'raster_mapalgebra_union(double precision, double precision, integer[], text[])'::regprocedure, '8BUI', 'FIRST') FROM map_shapes As m1 CROSS JOIN map_shapes As m2 WHERE m1.descrip = 'canvas' AND m2.descrip <> 'canvas' ORDER BY m2.bnum) As rasts) As foo; map bands overlay (canvas) (R: small road, G: circle, B: big road) CREATE OR REPLACE FUNCTION raster_mapalgebra_userargs( rast1 double precision, rast2 double precision, pos integer[], VARIADIC userargs text[] ) RETURNS double precision AS $$ DECLARE BEGIN CASE WHEN rast1 IS NOT NULL AND rast2 IS NOT NULL THEN RETURN least(userargs[1]::integer,(rast1 + rast2)/2.); WHEN rast1 IS NULL AND rast2 IS NULL THEN RETURN userargs[2]::integer; WHEN rast1 IS NULL THEN RETURN greatest(rast2,random()*userargs[3]::integer)::integer; ELSE RETURN greatest(rast1, random()*userargs[4]::integer)::integer; END CASE; RETURN NULL; END; $$ LANGUAGE 'plpgsql' VOLATILE COST 1000; SELECT ST_MapAlgebraFct(m1.rast, 1, m1.rast, 3, 'raster_mapalgebra_userargs(double precision, double precision, integer[], text[])'::regprocedure, '8BUI', 'INTERSECT', '100','200','200','0') FROM map_shapes As m1 WHERE m1.descrip = 'map bands overlay fct union (canvas)'; user defined with extra args and different bands from same raster , , , ST_MapAlgebraFctNgb 1-band version: Map Algebra Nearest Neighbor using user-defined PostgreSQL function. Return a raster which values are the result of a PLPGSQL user function involving a neighborhood of values from the input raster band. raster ST_MapAlgebraFctNgb raster rast integer band text pixeltype integer ngbwidth integer ngbheight regprocedure onerastngbuserfunc text nodatamode text[] VARIADIC args is deprecated as of 2.1.0. Use instead. (one raster version) Return a raster which values are the result of a PLPGSQL user function involving a neighborhood of values from the input raster band. The user function takes the neighborhood of pixel values as an array of numbers, for each pixel, returns the result from the user function, replacing pixel value of currently inspected pixel with the function result. rast Raster on which the user function is evaluated. band Band number of the raster to be evaluated. Default to 1. pixeltype The resulting pixel type of the output raster. Must be one listed in or left out or set to NULL. If not passed in or set to NULL, will default to the pixeltype of the rast. Results are truncated if they are larger than what is allowed for the pixeltype. ngbwidth The width of the neighborhood, in cells. ngbheight The height of the neighborhood, in cells. onerastngbuserfunc PLPGSQL/psql user function to apply to neighborhood pixels of a single band of a raster. The first element is a 2-dimensional array of numbers representing the rectangular pixel neighborhood nodatamode Defines what value to pass to the function for a neighborhood pixel that is nodata or NULL 'ignore': any NODATA values encountered in the neighborhood are ignored by the computation -- this flag must be sent to the user callback function, and the user function decides how to ignore it. 'NULL': any NODATA values encountered in the neighborhood will cause the resulting pixel to be NULL -- the user callback function is skipped in this case. 'value': any NODATA values encountered in the neighborhood are replaced by the reference pixel (the one in the center of the neighborhood). Note that if this value is NODATA, the behavior is the same as 'NULL' (for the affected neighborhood) args Arguments to pass into the user function. Availability: 2.0.0 Examples utilize the katrina raster loaded as a single tile described in http://trac.osgeo.org/gdal/wiki/frmts_wtkraster.html and then prepared in the examples -- -- A simple 'callback' user function that averages up all the values in a neighborhood. -- CREATE OR REPLACE FUNCTION rast_avg(matrix float[][], nodatamode text, variadic args text[]) RETURNS float AS $$ DECLARE _matrix float[][]; x1 integer; x2 integer; y1 integer; y2 integer; sum float; BEGIN _matrix := matrix; sum := 0; FOR x in array_lower(matrix, 1)..array_upper(matrix, 1) LOOP FOR y in array_lower(matrix, 2)..array_upper(matrix, 2) LOOP sum := sum + _matrix[x][y]; END LOOP; END LOOP; RETURN (sum*1.0/(array_upper(matrix,1)*array_upper(matrix,2) ))::integer ; END; $$ LANGUAGE 'plpgsql' IMMUTABLE COST 1000; -- now we apply to our raster averaging pixels within 2 pixels of each other in X and Y direction -- SELECT ST_MapAlgebraFctNgb(rast, 1, '8BUI', 4,4, 'rast_avg(float[][], text, text[])'::regprocedure, 'NULL', NULL) As nn_with_border FROM katrinas_rescaled limit 1; First band of our raster new raster after averaging pixels withing 4x4 pixels of each other , , ST_Reclass Creates a new raster composed of band types reclassified from original. The nband is the band to be changed. If nband is not specified assumed to be 1. All other bands are returned unchanged. Use case: convert a 16BUI band to a 8BUI and so forth for simpler rendering as viewable formats. raster ST_Reclass raster rast integer nband text reclassexpr text pixeltype double precision nodataval=NULL raster ST_Reclass raster rast reclassarg[] VARIADIC reclassargset raster ST_Reclass raster rast text reclassexpr text pixeltype Creates a new raster formed by applying a valid PostgreSQL algebraic operation defined by the reclassexpr on the input raster (rast). If no band is specified band 1 is assumed. The new raster will have the same georeference, width, and height as the original raster. Bands not designated will come back unchanged. Refer to for description of valid reclassification expressions. The bands of the new raster will have pixel type of pixeltype. If reclassargset is passed in then each reclassarg defines behavior of each band generated. Availability: 2.0.0 Create a new raster from the original where band 2 is converted from 8BUI to 4BUI and all values from 101-254 are set to nodata value. ALTER TABLE dummy_rast ADD COLUMN reclass_rast raster; UPDATE dummy_rast SET reclass_rast = ST_Reclass(rast,2,'0-87:1-10, 88-100:11-15, 101-254:0-0', '4BUI',0) WHERE rid = 2; SELECT i as col, j as row, ST_Value(rast,2,i,j) As origval, ST_Value(reclass_rast, 2, i, j) As reclassval, ST_Value(reclass_rast, 2, i, j, false) As reclassval_include_nodata FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j WHERE rid = 2; col | row | origval | reclassval | reclassval_include_nodata -----+-----+---------+------------+--------------------------- 1 | 1 | 78 | 9 | 9 2 | 1 | 98 | 14 | 14 3 | 1 | 122 | | 0 1 | 2 | 96 | 14 | 14 2 | 2 | 118 | | 0 3 | 2 | 180 | | 0 1 | 3 | 99 | 15 | 15 2 | 3 | 112 | | 0 3 | 3 | 169 | | 0 Create a new raster from the original where band 1,2,3 is converted to 1BB,4BUI, 4BUI respectively and reclassified. Note this uses the variadic reclassarg argument which can take as input an indefinite number of reclassargs (theoretically as many bands as you have) UPDATE dummy_rast SET reclass_rast = ST_Reclass(rast, ROW(2,'0-87]:1-10, (87-100]:11-15, (101-254]:0-0', '4BUI',NULL)::reclassarg, ROW(1,'0-253]:1, 254:0', '1BB', NULL)::reclassarg, ROW(3,'0-70]:1, (70-86:2, [86-150):3, [150-255:4', '4BUI', NULL)::reclassarg ) WHERE rid = 2; SELECT i as col, j as row,ST_Value(rast,1,i,j) As ov1, ST_Value(reclass_rast, 1, i, j) As rv1, ST_Value(rast,2,i,j) As ov2, ST_Value(reclass_rast, 2, i, j) As rv2, ST_Value(rast,3,i,j) As ov3, ST_Value(reclass_rast, 3, i, j) As rv3 FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j WHERE rid = 2; col | row | ov1 | rv1 | ov2 | rv2 | ov3 | rv3 ----+-----+-----+-----+-----+-----+-----+----- 1 | 1 | 253 | 1 | 78 | 9 | 70 | 1 2 | 1 | 254 | 0 | 98 | 14 | 86 | 3 3 | 1 | 253 | 1 | 122 | 0 | 100 | 3 1 | 2 | 253 | 1 | 96 | 14 | 80 | 2 2 | 2 | 254 | 0 | 118 | 0 | 108 | 3 3 | 2 | 254 | 0 | 180 | 0 | 162 | 4 1 | 3 | 250 | 1 | 99 | 15 | 90 | 3 2 | 3 | 254 | 0 | 112 | 0 | 108 | 3 3 | 3 | 254 | 0 | 169 | 0 | 175 | 4 Create a new 3 band (8BUI,8BUI,8BUI viewable raster) from a raster that has only one 32bf band ALTER TABLE wind ADD COLUMN rast_view raster; UPDATE wind set rast_view = ST_AddBand( NULL, ARRAY[ ST_Reclass(rast, 1,'0.1-10]:1-10,9-10]:11,(11-33:0'::text, '8BUI'::text,0), ST_Reclass(rast,1, '11-33):0-255,[0-32:0,(34-1000:0'::text, '8BUI'::text,0), ST_Reclass(rast,1,'0-32]:0,(32-100:100-255'::text, '8BUI'::text,0) ] ); , , , , , ST_Union Returns the union of a set of raster tiles into a single raster composed of 1 or more bands. raster ST_Union setof raster rast raster ST_Union setof raster rast unionarg[] unionargset raster ST_Union setof raster rast integer nband raster ST_Union setof raster rast text uniontype raster ST_Union setof raster rast integer nband text uniontype Returns the union of a set of raster tiles into a single raster composed of at least one band. The resulting raster's extent is the extent of the whole set. In the case of intersection, the resulting value is defined by uniontype which is one of the following: LAST (default), FIRST, MIN, MAX, COUNT, SUM, MEAN, RANGE. In order for rasters to be unioned, they most all have the same alignment. Use and for more details and help. One way to fix alignment issues is to use and use the same reference raster for alignment. Availability: 2.0.0 Enhanced: 2.1.0 Improved Speed (fully C-Based). Availability: 2.1.0 ST_Union(rast, unionarg) variant was introduced. Enhanced: 2.1.0 ST_Union(rast) (variant 1) unions all bands of all input rasters. Prior versions of PostGIS assumed the first band. Enhanced: 2.1.0 ST_Union(rast, uniontype) (variant 4) unions all bands of all input rasters. -- this creates a single band from first band of raster tiles -- that form the original file system tile SELECT filename, ST_Union(rast,1) As file_rast FROM sometable WHERE filename IN('dem01', 'dem02') GROUP BY filename; -- this creates a multi band raster collecting all the tiles that intersect a line -- Note: In 2.0, this would have just returned a single band raster -- , new union works on all bands by default -- this is equivalent to unionarg: ARRAY[ROW(1, 'LAST'), ROW(2, 'LAST'), ROW(3, 'LAST')]::unionarg[] SELECT ST_Union(rast) FROM aerials.boston WHERE ST_Intersects(rast, ST_GeomFromText('LINESTRING(230486 887771, 230500 88772)',26986) ); Here we use the longer syntax if we only wanted a subset of bands or we want to change order of bands -- this creates a multi band raster collecting all the tiles that intersect a line SELECT ST_Union(rast,ARRAY[ROW(2, 'LAST'), ROW(1, 'LAST'), ROW(3, 'LAST')]::unionarg[]) FROM aerials.boston WHERE ST_Intersects(rast, ST_GeomFromText('LINESTRING(230486 887771, 230500 88772)',26986) ); , , , , ST_Distinct4ma Raster processing function that calculates the number of unique pixel values in a neighborhood. float8 ST_Distinct4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Distinct4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the number of unique pixel values in a neighborhood of pixels. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, NULL, 1, 1, 'st_distinct4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 3 (1 row) , , , , , , , ST_InvDistWeight4ma Raster processing function that interpolates a pixel's value from the pixel's neighborhood. double precision ST_InvDistWeight4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate an interpolated value for a pixel using the Inverse Distance Weighted method. There are two optional parameters that can be passed through userargs. The first parameter is the power factor (variable k in the equation below) between 0 and 1 used in the Inverse Distance Weighted equation. If not specified, default value is 1. The second parameter is the weight percentage applied only when the value of the pixel of interest is included with the interpolated value from the neighborhood. If not specified and the pixel of interest has a value, that value is returned. The basic inverse distance weight equation is: k = power factor, a real number between 0 and 1 This function is a specialized callback function for use as a callback parameter to . Availability: 2.1.0 -- NEEDS EXAMPLE , ST_Max4ma Raster processing function that calculates the maximum pixel value in a neighborhood. float8 ST_Max4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Max4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the maximum pixel value in a neighborhood of pixels. For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, NULL, 1, 1, 'st_max4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 254 (1 row) , , , , , , , ST_Mean4ma Raster processing function that calculates the mean pixel value in a neighborhood. float8 ST_Mean4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Mean4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the mean pixel value in a neighborhood of pixels. For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, '32BF', 1, 1, 'st_mean4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+------------------ 2 | 253.222229003906 (1 row) SELECT rid, st_value( ST_MapAlgebra(rast, 1, 'st_mean4ma(double precision[][][], integer[][], text[])'::regprocedure,'32BF', 'FIRST', NULL, 1, 1) , 2, 2) FROM dummy_rast WHERE rid = 2; rid | st_value -----+------------------ 2 | 253.222229003906 (1 row) , , , , , , ST_Min4ma Raster processing function that calculates the minimum pixel value in a neighborhood. float8 ST_Min4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Min4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the minimum pixel value in a neighborhood of pixels. For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, NULL, 1, 1, 'st_min4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 250 (1 row) , , , , , , , ST_MinDist4ma Raster processing function that returns the minimum distance (in number of pixels) between the pixel of interest and a neighboring pixel with value. double precision ST_MinDist4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Return the shortest distance (in number of pixels) between the pixel of interest and the closest pixel with value in the neighborhood. The intent of this function is to provide an informative data point that helps infer the usefulness of the pixel of interest's interpolated value from . This function is particularly useful when the neighborhood is sparsely populated. This function is a specialized callback function for use as a callback parameter to . Availability: 2.1.0 -- NEEDS EXAMPLE , ST_Range4ma Raster processing function that calculates the range of pixel values in a neighborhood. float8 ST_Range4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Range4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the range of pixel values in a neighborhood of pixels. For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, NULL, 1, 1, 'st_range4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 4 (1 row) , , , , , , , ST_StdDev4ma Raster processing function that calculates the standard deviation of pixel values in a neighborhood. float8 ST_StdDev4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_StdDev4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the standard deviation of pixel values in a neighborhood of pixels. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, '32BF', 1, 1, 'st_stddev4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+------------------ 2 | 1.30170822143555 (1 row) , , , , , , , ST_Sum4ma Raster processing function that calculates the sum of all pixel values in a neighborhood. float8 ST_Sum4ma float8[][] matrix text nodatamode text[] VARIADIC args double precision ST_Sum4ma double precision[][][] value integer[][] pos text[] VARIADIC userargs Calculate the sum of all pixel values in a neighborhood of pixels. For Variant 2, a substitution value for NODATA pixels can be specified by passing that value to userargs. Variant 1 is a specialized callback function for use as a callback parameter to . Variant 2 is a specialized callback function for use as a callback parameter to . Use of Variant 1 is discouraged since has been deprecated as of 2.1.0. Availability: 2.0.0 Enhanced: 2.1.0 Addition of Variant 2 SELECT rid, st_value( st_mapalgebrafctngb(rast, 1, '32BF', 1, 1, 'st_sum4ma(float[][],text,text[])'::regprocedure, 'ignore', NULL), 2, 2 ) FROM dummy_rast WHERE rid = 2; rid | st_value -----+---------- 2 | 2279 (1 row) , , , , , , , ST_Aspect Returns the aspect (in degrees by default) of an elevation raster band. Useful for analyzing terrain. raster ST_Aspect raster rast integer band=1 text pixeltype=32BF text units=DEGREES boolean interpolate_nodata=FALSE raster ST_Aspect raster rast integer band raster customextent text pixeltype=32BF text units=DEGREES boolean interpolate_nodata=FALSE Returns the aspect (in degrees by default) of an elevation raster band. Utilizes map algebra and applies the aspect equation to neighboring pixels. units indicates the units of the aspect. Possible values are: RADIANS, DEGREES (default). When units = RADIANS, values are between 0 and 2 * pi radians measured clockwise from North. When units = DEGREES, values are between 0 and 360 degrees measured clockwise from North. If slope of pixel is zero, aspect of pixel is -1. For more information about Slope, Aspect and Hillshade, please refer to ESRI - How hillshade works and ERDAS Field Guide - Aspect Images. Availability: 2.0.0 Enhanced: 2.1.0 Uses ST_MapAlgebra() and added optional interpolate_nodata function parameter Changed: 2.1.0 In prior versions, return values were in radians. Now, return values default to degrees WITH foo AS ( SELECT ST_SetValues( ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1], [1, 2, 2, 2, 1], [1, 2, 3, 2, 1], [1, 2, 2, 2, 1], [1, 1, 1, 1, 1] ]::double precision[][] ) AS rast ) SELECT ST_DumpValues(ST_Aspect(rast, 1, '32BF')) FROM foo st_dumpvalues ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ---------------------------------- (1,"{{315,341.565063476562,0,18.4349479675293,45},{288.434936523438,315,0,45,71.5650482177734},{270,270,-1,90,90},{251.565048217773,225,180,135,108.434951782227},{225,198.43495178 2227,180,161.565048217773,135}}") (1 row) Complete example of tiles of a coverage. This query only works with PostgreSQL 9.1 or higher. WITH foo AS ( SELECT ST_Tile( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(6, 6, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999 ), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 2, 1], [1, 2, 2, 3, 3, 1], [1, 1, 3, 2, 1, 1], [1, 2, 2, 1, 2, 1], [1, 1, 1, 1, 1, 1] ]::double precision[] ), 2, 2 ) AS rast ) SELECT t1.rast, ST_Aspect(ST_Union(t2.rast), 1, t1.rast) FROM foo t1 CROSS JOIN foo t2 WHERE ST_Intersects(t1.rast, t2.rast) GROUP BY t1.rast; , , , , , ST_HillShade Returns the hypothetical illumination of an elevation raster band using provided azimuth, altitude, brightness and scale inputs. raster ST_HillShade raster rast integer band=1 text pixeltype=32BF double precision azimuth=315 double precision altitude=45 double precision max_bright=255 double precision scale=1.0 boolean interpolate_nodata=FALSE raster ST_HillShade raster rast integer band raster customextent text pixeltype=32BF double precision azimuth=315 double precision altitude=45 double precision max_bright=255 double precision scale=1.0 boolean interpolate_nodata=FALSE Returns the hypothetical illumination of an elevation raster band using the azimuth, altitude, brightness, and scale inputs. Utilizes map algebra and applies the hill shade equation to neighboring pixels. Return pixel values are between 0 and 255. azimuth is a value between 0 and 360 degrees measured clockwise from North. altitude is a value between 0 and 90 degrees where 0 degrees is at the horizon and 90 degrees is directly overhead. max_bright is a value between 0 and 255 with 0 as no brightness and 255 as max brightness. scale is the ratio of vertical units to horizontal. For Feet:LatLon use scale=370400, for Meters:LatLon use scale=111120. If interpolate_nodata is TRUE, values for NODATA pixels from the input raster will be interpolated using before computing the hillshade illumination. For more information about Hillshade, please refer to How hillshade works. Availability: 2.0.0 Enhanced: 2.1.0 Uses ST_MapAlgebra() and added optional interpolate_nodata function parameter Changed: 2.1.0 In prior versions, azimuth and altitude were expressed in radians. Now, azimuth and altitude are expressed in degrees WITH foo AS ( SELECT ST_SetValues( ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1], [1, 2, 2, 2, 1], [1, 2, 3, 2, 1], [1, 2, 2, 2, 1], [1, 1, 1, 1, 1] ]::double precision[][] ) AS rast ) SELECT ST_DumpValues(ST_Hillshade(rast, 1, '32BF')) FROM foo st_dumpvalues ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ----------------------------------------------------------------------- (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,251.32763671875,220.749786376953,147.224319458008,NULL},{NULL,220.749786376953,180.312225341797,67.7497863769531,NULL},{NULL,147.224319458008 ,67.7497863769531,43.1210060119629,NULL},{NULL,NULL,NULL,NULL,NULL}}") (1 row) Complete example of tiles of a coverage. This query only works with PostgreSQL 9.1 or higher. WITH foo AS ( SELECT ST_Tile( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(6, 6, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999 ), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 2, 1], [1, 2, 2, 3, 3, 1], [1, 1, 3, 2, 1, 1], [1, 2, 2, 1, 2, 1], [1, 1, 1, 1, 1, 1] ]::double precision[] ), 2, 2 ) AS rast ) SELECT t1.rast, ST_Hillshade(ST_Union(t2.rast), 1, t1.rast) FROM foo t1 CROSS JOIN foo t2 WHERE ST_Intersects(t1.rast, t2.rast) GROUP BY t1.rast; , , , , , ST_Roughness Returns a raster with the calculated "roughness" of a DEM. raster ST_Roughness raster rast integer nband raster customextent text pixeltype="32BF" boolean interpolate_nodata=FALSE Calculates the "roughness" of a DEM, by subtracting the maximum from the minimum for a given area. Availability: 2.1.0 -- needs examples , , , , , ST_Slope Returns the slope (in degrees by default) of an elevation raster band. Useful for analyzing terrain. raster ST_Slope raster rast integer nband=1 text pixeltype=32BF text units=DEGREES double precision scale=1.0 boolean interpolate_nodata=FALSE raster ST_Slope raster rast integer nband raster customextent text pixeltype=32BF text units=DEGREES double precision scale=1.0 boolean interpolate_nodata=FALSE Returns the slope (in degrees by default) of an elevation raster band. Utilizes map algebra and applies the slope equation to neighboring pixels. units indicates the units of the slope. Possible values are: RADIANS, DEGREES (default), PERCENT. scale is the ratio of vertical units to horizontal. For Feet:LatLon use scale=370400, for Meters:LatLon use scale=111120. If interpolate_nodata is TRUE, values for NODATA pixels from the input raster will be interpolated using before computing the surface slope. For more information about Slope, Aspect and Hillshade, please refer to ESRI - How hillshade works and ERDAS Field Guide - Slope Images. Availability: 2.0.0 Enhanced: 2.1.0 Uses ST_MapAlgebra() and added optional units, scale, interpolate_nodata function parameters Changed: 2.1.0 In prior versions, return values were in radians. Now, return values default to degrees WITH foo AS ( SELECT ST_SetValues( ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1], [1, 2, 2, 2, 1], [1, 2, 3, 2, 1], [1, 2, 2, 2, 1], [1, 1, 1, 1, 1] ]::double precision[][] ) AS rast ) SELECT ST_DumpValues(ST_Slope(rast, 1, '32BF')) FROM foo st_dumpvalues ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ --------------------------------------------------------------------- (1,"{{10.0249881744385,21.5681285858154,26.5650520324707,21.5681285858154,10.0249881744385},{21.5681285858154,35.2643890380859,36.8698959350586,35.2643890380859,21.5681285858154}, {26.5650520324707,36.8698959350586,0,36.8698959350586,26.5650520324707},{21.5681285858154,35.2643890380859,36.8698959350586,35.2643890380859,21.5681285858154},{10.0249881744385,21. 5681285858154,26.5650520324707,21.5681285858154,10.0249881744385}}") (1 row) Complete example of tiles of a coverage. This query only works with PostgreSQL 9.1 or higher. WITH foo AS ( SELECT ST_Tile( ST_SetValues( ST_AddBand( ST_MakeEmptyRaster(6, 6, 0, 0, 1, -1, 0, 0, 0), 1, '32BF', 0, -9999 ), 1, 1, 1, ARRAY[ [1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 2, 1], [1, 2, 2, 3, 3, 1], [1, 1, 3, 2, 1, 1], [1, 2, 2, 1, 2, 1], [1, 1, 1, 1, 1, 1] ]::double precision[] ), 2, 2 ) AS rast ) SELECT t1.rast, ST_Slope(ST_Union(t2.rast), 1, t1.rast) FROM foo t1 CROSS JOIN foo t2 WHERE ST_Intersects(t1.rast, t2.rast) GROUP BY t1.rast; , , , , , ST_TPI Returns a raster with the calculated Topographic Position Index. raster ST_TPI raster rast integer nband raster customextent text pixeltype="32BF" boolean interpolate_nodata=FALSE Calculates the Topographic Position Index, which is defined as the folcal mean with radius of one minus the center cell. This function only supports a focalmean radius of one. Availability: 2.1.0 -- needs examples , , , , , ST_TRI Returns a raster with the calculated Terrain Ruggedness Index. raster ST_TRI raster rast integer nband raster customextent text pixeltype="32BF" boolean interpolate_nodata=FALSE Terrain Ruggedness Index is calculated by comparing a central pixel with its neighbors, taking the absolute values of the differences, and averaging the result. This function only supports a focalmean radius of one. Availability: 2.1.0 -- needs examples , , , , , Box3D Returns the box 3d representation of the enclosing box of the raster. box3d Box3D raster rast Returns the box representing the extent of the raster. The polygon is defined by the corner points of the bounding box ((MINX, MINY), (MAXX, MAXY)) Changed: 2.0.0 In pre-2.0 versions, there used to be a box2d instead of box3d. Since box2d is a deprecated type, this was changed to box3d. SELECT rid, Box3D(rast) AS rastbox FROM dummy_rast; rid | rastbox ----+------------------------------------------------- 1 | BOX3D(0.5 0.5 0,20.5 60.5 0) 2 | BOX3D(3427927.75 5793243.5 0,3427928 5793244 0) ST_ConvexHull Return the convex hull geometry of the raster including pixel values equal to BandNoDataValue. For regular shaped and non-skewed rasters, this gives the same result as ST_Envelope so only useful for irregularly shaped or skewed rasters. geometry ST_ConvexHull raster rast Return the convex hull geometry of the raster including the NoDataBandValue band pixels. For regular shaped and non-skewed rasters, this gives more or less the same result as ST_Envelope so only useful for irregularly shaped or skewed rasters. ST_Envelope floors the coordinates and hence add a little buffer around the raster so the answer is subtly different from ST_ConvexHull which does not floor. Refer to PostGIS Raster Specification for a diagram of this. -- Note envelope and convexhull are more or less the same SELECT ST_AsText(ST_ConvexHull(rast)) As convhull, ST_AsText(ST_Envelope(rast)) As env FROM dummy_rast WHERE rid=1; convhull | env --------------------------------------------------------+------------------------------------ POLYGON((0.5 0.5,20.5 0.5,20.5 60.5,0.5 60.5,0.5 0.5)) | POLYGON((0 0,20 0,20 60,0 60,0 0)) -- now we skew the raster -- note how the convex hull and envelope are now different SELECT ST_AsText(ST_ConvexHull(rast)) As convhull, ST_AsText(ST_Envelope(rast)) As env FROM (SELECT ST_SetRotation(rast, 0.1, 0.1) As rast FROM dummy_rast WHERE rid=1) As foo; convhull | env --------------------------------------------------------+------------------------------------ POLYGON((0.5 0.5,20.5 1.5,22.5 61.5,2.5 60.5,0.5 0.5)) | POLYGON((0 0,22 0,22 61,0 61,0 0)) , , , ST_DumpAsPolygons Returns a set of geomval (geom,val) rows, from a given raster band. If no band number is specified, band num defaults to 1. setof geomval ST_DumpAsPolygons raster rast integer band_num=1 boolean exclude_nodata_value=TRUE This is a set-returning function (SRF). It returns a set of geomval rows, formed by a geometry (geom) and a pixel band value (val). Each polygon is the union of all pixels for that band that have the same pixel value denoted by val. ST_DumpAsPolygon is useful for polygonizing rasters. It is the reverse of a GROUP BY in that it creates new rows. For example it can be used to expand a single raster into multiple POLYGONS/MULTIPOLYGONS. Availability: Requires GDAL 1.7 or higher. If there is a no data value set for a band, pixels with that value will not be returned. If you only care about count of pixels with a given value in a raster, it is faster to use . This is different than ST_PixelAsPolygons where one geometry is returned for each pixel regardless of pixel value. SELECT val, ST_AsText(geom) As geomwkt FROM ( SELECT (ST_DumpAsPolygons(rast)).* FROM dummy_rast WHERE rid = 2 ) As foo WHERE val BETWEEN 249 and 251 ORDER BY val; val | geomwkt -----+-------------------------------------------------------------------------- 249 | POLYGON((3427927.95 5793243.95,3427927.95 5793243.85,3427928 5793243.85, 3427928 5793243.95,3427927.95 5793243.95)) 250 | POLYGON((3427927.75 5793243.9,3427927.75 5793243.85,3427927.8 5793243.85, 3427927.8 5793243.9,3427927.75 5793243.9)) 250 | POLYGON((3427927.8 5793243.8,3427927.8 5793243.75,3427927.85 5793243.75, 3427927.85 5793243.8, 3427927.8 5793243.8)) 251 | POLYGON((3427927.75 5793243.85,3427927.75 5793243.8,3427927.8 5793243.8, 3427927.8 5793243.85,3427927.75 5793243.85)) , , , ST_Envelope Returns the polygon representation of the extent of the raster. geometry ST_Envelope raster rast Returns the polygon representation of the extent of the raster in spatial coordinate units defined by srid. It is a float8 minimum bounding box represented as a polygon. The polygon is defined by the corner points of the bounding box ((MINX, MINY), (MINX, MAXY), (MAXX, MAXY), (MAXX, MINY), (MINX, MINY)) SELECT rid, ST_AsText(ST_Envelope(rast)) As envgeomwkt FROM dummy_rast; rid | envgeomwkt -----+-------------------------------------------------------------------- 1 | POLYGON((0 0,20 0,20 60,0 60,0 0)) 2 | POLYGON((3427927 5793243,3427928 5793243, 3427928 5793244,3427927 5793244, 3427927 5793243)) , , ST_MinConvexHull Return the convex hull geometry of the raster excluding NODATA pixels. geometry ST_MinConvexHull raster rast integer nband=NULL Return the convex hull geometry of the raster excluding NODATA pixels. If nband is NULL, all bands of the raster are considered. Availability: 2.1.0 WITH foo AS ( SELECT ST_SetValues( ST_SetValues( ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(9, 9, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0), 2, '8BUI', 1, 0), 1, 1, 1, ARRAY[ [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0, 1], [0, 0, 0, 1, 1, 0, 0, 0, 0], [0, 0, 0, 1, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0] ]::double precision[][] ), 2, 1, 1, ARRAY[ [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [1, 0, 0, 0, 0, 1, 0, 0, 0], [0, 0, 0, 0, 1, 1, 0, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0, 0, 0] ]::double precision[][] ) AS rast ) SELECT ST_AsText(ST_ConvexHull(rast)) AS hull, ST_AsText(ST_MinConvexHull(rast)) AS mhull, ST_AsText(ST_MinConvexHull(rast, 1)) AS mhull_1, ST_AsText(ST_MinConvexHull(rast, 2)) AS mhull_2 FROM foo hull | mhull | mhull_1 | mhull_2 ----------------------------------+-------------------------------------+-------------------------------------+------------------------------------- POLYGON((0 0,9 0,9 -9,0 -9,0 0)) | POLYGON((0 -3,9 -3,9 -9,0 -9,0 -3)) | POLYGON((3 -3,9 -3,9 -6,3 -6,3 -3)) | POLYGON((0 -3,6 -3,6 -9,0 -9,0 -3)) , , , ST_Polygon Returns a multipolygon geometry formed by the union of pixels that have a pixel value that is not no data value. If no band number is specified, band num defaults to 1. geometry ST_Polygon raster rast integer band_num=1 Availability: 0.1.6 Requires GDAL 1.7 or higher. Enhanced: 2.1.0 Improved Speed (fully C-Based) and the returning multipolygon is ensured to be valid. Changed: 2.1.0 In prior versions would sometimes return a polygon, changed to always return multipolygon. -- by default no data band value is 0 or not set, so polygon will return a square polygon SELECT ST_AsText(ST_Polygon(rast)) As geomwkt FROM dummy_rast WHERE rid = 2; geomwkt -------------------------------------------- MULTIPOLYGON(((3427927.75 5793244,3427928 5793244,3427928 5793243.75,3427927.75 5793243.75,3427927.75 5793244))) -- now we change the no data value of first band UPDATE dummy_rast SET rast = ST_SetBandNoDataValue(rast,1,254) WHERE rid = 2; SELECt rid, ST_BandNoDataValue(rast) from dummy_rast where rid = 2; -- ST_Polygon excludes the pixel value 254 and returns a multipolygon SELECT ST_AsText(ST_Polygon(rast)) As geomwkt FROM dummy_rast WHERE rid = 2; geomwkt --------------------------------------------------------- MULTIPOLYGON(((3427927.9 5793243.95,3427927.85 5793243.95,3427927.85 5793244,3427927.9 5793244,3427927.9 5793243.95)),((3427928 5793243.85,3427928 5793243.8,3427927.95 5793243.8,3427927.95 5793243.85,3427927.9 5793243.85,3427927.9 5793243.9,3427927.9 5793243.95,3427927.95 5793243.95,3427928 5793243.95,3427928 5793243.85)),((3427927.8 5793243.75,3427927.75 5793243.75,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,3427927.8 5793243.9,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75,3427927.8 5793243.75))) -- Or if you want the no data value different for just one time SELECT ST_AsText( ST_Polygon( ST_SetBandNoDataValue(rast,1,252) ) ) As geomwkt FROM dummy_rast WHERE rid =2; geomwkt --------------------------------- MULTIPOLYGON(((3427928 5793243.85,3427928 5793243.8,3427928 5793243.75,3427927.85 5793243.75,3427927.8 5793243.75,3427927.8 5793243.8,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,3427927.85 5793244,3427927.9 5793244,3427928 5793244,3427928 5793243.95,3427928 5793243.85),(3427927.9 5793243.9,3427927.9 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9,3427927.9 5793243.9))) , && Returns TRUE if A's bounding box intersects B's bounding box. boolean && raster A raster B boolean && raster A geometry B boolean && geometry B raster A The && operator returns TRUE if the bounding box of raster/geometr A intersects the bounding box of raster/geometr B. This operand will make use of any indexes that may be available on the rasters. Availability: 2.0.0 SELECT A.rid As a_rid, B.rid As b_rid, A.rast && B.rast As intersect FROM dummy_rast AS A CROSS JOIN dummy_rast AS B LIMIT 3; a_rid | b_rid | intersect -------+-------+--------- 2 | 2 | t 2 | 3 | f 2 | 1 | f &< Returns TRUE if A's bounding box is to the left of B's. boolean &< raster A raster B The &< operator returns TRUE if the bounding box of raster A overlaps or is to the left of the bounding box of raster B, or more accurately, overlaps or is NOT to the right of the bounding box of raster B. This operand will make use of any indexes that may be available on the geometries. SELECT A.rid As a_rid, B.rid As b_rid, A.rast &< B.rast As overleft FROM dummy_rast AS A CROSS JOIN dummy_rast AS B; a_rid | b_rid | overleft ------+-------+---------- 2 | 2 | t 2 | 3 | f 2 | 1 | f 3 | 2 | t 3 | 3 | t 3 | 1 | f 1 | 2 | t 1 | 3 | t 1 | 1 | t &> Returns TRUE if A's bounding box is to the right of B's. boolean &> raster A raster B The &> operator returns TRUE if the bounding box of raster A overlaps or is to the right of the bounding box of raster B, or more accurately, overlaps or is NOT to the left of the bounding box of raster B. This operand will make use of any indexes that may be available on the geometries. SELECT A.rid As a_rid, B.rid As b_rid, A.rast &> B.rast As overright FROM dummy_rast AS A CROSS JOIN dummy_rast AS B; a_rid | b_rid | overright -------+-------+---------- 2 | 2 | t 2 | 3 | t 2 | 1 | t 3 | 2 | f 3 | 3 | t 3 | 1 | f 1 | 2 | f 1 | 3 | t 1 | 1 | t = Returns TRUE if A's bounding box is the same as B's. Uses double precision bounding box. boolean = raster A raster B The = operator returns TRUE if the bounding box of raster A is the same as the bounding box of raster B. PostgreSQL uses the =, <, and > operators defined for rasters to perform internal orderings and comparison of rasters (ie. in a GROUP BY or ORDER BY clause). This operand will NOT make use of any indexes that may be available on the rasters. Use instead. This operator exists mostly so one can group by the raster column. Availability: 2.1.0 @ Returns TRUE if A's bounding box is contained by B's. Uses double precision bounding box. boolean @ raster A raster B boolean @ geometry A raster B boolean @ raster B geometry A The @ operator returns TRUE if the bounding box of raster/geometry A is contained by bounding box of raster/geometr B. This operand will use spatial indexes on the rasters. Availability: 2.0.0 raster @ raster, raster @ geometry introduced Availability: 2.0.5 geometry @ raster introduced ~= Returns TRUE if A's bounding box is the same as B's. boolean ~= raster A raster B The ~= operator returns TRUE if the bounding box of raster A is the same as the bounding box of raster B. This operand will make use of any indexes that may be available on the rasters. Availability: 2.0.0 Very useful usecase is for taking two sets of single band rasters that are of the same chunk but represent different themes and creating a multi-band raster SELECT ST_AddBand(prec.rast, alt.rast) As new_rast FROM prec INNER JOIN alt ON (prec.rast ~= alt.rast); , ~ Returns TRUE if A's bounding box is contains B's. Uses double precision bounding box. boolean ~ raster A raster B boolean ~ geometry A raster B boolean ~ raster B geometry A The ~ operator returns TRUE if the bounding box of raster/geometry A is contains bounding box of raster/geometr B. This operand will use spatial indexes on the rasters. Availability: 2.0.0 ST_Contains Return true if no points of raster rastB lie in the exterior of raster rastA and at least one point of the interior of rastB lies in the interior of rastA. boolean ST_Contains raster rastA integer nbandA raster rastB integer nbandB boolean ST_Contains raster rastA raster rastB Raster rastA contains rastB if and only if no points of rastB lie in the exterior of rastA and at least one point of the interior of rastB lies in the interior of rastA. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Contains(ST_Polygon(raster), geometry) or ST_Contains(geometry, ST_Polygon(raster)). ST_Contains() is the inverse of ST_Within(). So, ST_Contains(rastA, rastB) implies ST_Within(rastB, rastA). Availability: 2.1.0 -- specified band numbers SELECT r1.rid, r2.rid, ST_Contains(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 1; NOTICE: The first raster provided has no bands rid | rid | st_contains -----+-----+------------- 1 | 1 | 1 | 2 | f -- no band numbers specified SELECT r1.rid, r2.rid, ST_Contains(r1.rast, r2.rast) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 1; rid | rid | st_contains -----+-----+------------- 1 | 1 | t 1 | 2 | f , ST_ContainsProperly Return true if rastB intersects the interior of rastA but not the boundary or exterior of rastA. boolean ST_ContainsProperly raster rastA integer nbandA raster rastB integer nbandB boolean ST_ContainsProperly raster rastA raster rastB Raster rastA contains properly rastB if rastB intersects the interior of rastA but not the boundary or exterior of rastA. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. Raster rastA does not contain properly itself but does contain itself. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_ContainsProperly(ST_Polygon(raster), geometry) or ST_ContainsProperly(geometry, ST_Polygon(raster)). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_ContainsProperly(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_containsproperly -----+-----+--------------------- 2 | 1 | f 2 | 2 | f , ST_Covers Return true if no points of raster rastB lie outside raster rastA. boolean ST_Covers raster rastA integer nbandA raster rastB integer nbandB boolean ST_Covers raster rastA raster rastB Raster rastA covers rastB if and only if no points of rastB lie in the exterior of rastA. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Covers(ST_Polygon(raster), geometry) or ST_Covers(geometry, ST_Polygon(raster)). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_Covers(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_covers -----+-----+----------- 2 | 1 | f 2 | 2 | t , ST_CoveredBy Return true if no points of raster rastA lie outside raster rastB. boolean ST_CoveredBy raster rastA integer nbandA raster rastB integer nbandB boolean ST_CoveredBy raster rastA raster rastB Raster rastA is covered by rastB if and only if no points of rastA lie in the exterior of rastB. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_CoveredBy(ST_Polygon(raster), geometry) or ST_CoveredBy(geometry, ST_Polygon(raster)). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_CoveredBy(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_coveredby -----+-----+-------------- 2 | 1 | f 2 | 2 | t , ST_Disjoint Return true if raster rastA does not spatially intersect rastB. boolean ST_Disjoint raster rastA integer nbandA raster rastB integer nbandB boolean ST_Disjoint raster rastA raster rastB Raster rastA and rastB are disjointed if they do not share any space together. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function does NOT use any indexes. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Disjoint(ST_Polygon(raster), geometry). Availability: 2.1.0 -- rid = 1 has no bands, hence the NOTICE and the NULL value for st_disjoint SELECT r1.rid, r2.rid, ST_Disjoint(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; NOTICE: The second raster provided has no bands rid | rid | st_disjoint -----+-----+------------- 2 | 1 | 2 | 2 | f -- this time, without specifying band numbers SELECT r1.rid, r2.rid, ST_Disjoint(r1.rast, r2.rast) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_disjoint -----+-----+------------- 2 | 1 | t 2 | 2 | f ST_Intersects Return true if raster rastA spatially intersects raster rastB. boolean ST_Intersects raster rastA integer nbandA raster rastB integer nbandB boolean ST_Intersects raster rastA raster rastB boolean ST_Intersects raster rast integer nband geometry geommin boolean ST_Intersects raster rast geometry geommin integer nband=NULL boolean ST_Intersects geometry geommin raster rast integer nband=NULL Return true if raster rastA spatially intersects raster rastB. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. Enhanced: 2.0.0 support raster/raster intersects was introduced. Changed: 2.1.0 The behavior of the ST_Intersects(raster, geometry) variants changed to match that of ST_Intersects(geometry, raster). -- different bands of same raster SELECT ST_Intersects(rast, 2, rast, 3) FROM dummy_rast WHERE rid = 2; st_intersects --------------- t , ST_Overlaps Return true if raster rastA and rastB intersect but one does not completely contain the other. boolean ST_Overlaps raster rastA integer nbandA raster rastB integer nbandB boolean ST_Overlaps raster rastA raster rastB Return true if raster rastA spatially overlaps raster rastB. This means that rastA and rastB intersect but one does not completely contain the other. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Overlaps(ST_Polygon(raster), geometry). Availability: 2.1.0 -- comparing different bands of same raster SELECT ST_Overlaps(rast, 1, rast, 2) FROM dummy_rast WHERE rid = 2; st_overlaps ------------- f ST_Touches Return true if raster rastA and rastB have at least one point in common but their interiors do not intersect. boolean ST_Touches raster rastA integer nbandA raster rastB integer nbandB boolean ST_Touches raster rastA raster rastB Return true if raster rastA spatially touches raster rastB. This means that rastA and rastB have at least one point in common but their interiors do not intersect. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This function will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Touches(ST_Polygon(raster), geometry). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_Touches(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_touches -----+-----+------------ 2 | 1 | f 2 | 2 | f ST_SameAlignment Returns true if rasters have same skew, scale, spatial ref, and offset (pixels can be put on same grid without cutting into pixels) and false if they don't with notice detailing issue. boolean ST_SameAlignment raster rastA raster rastB boolean ST_SameAlignment double precision ulx1 double precision uly1 double precision scalex1 double precision scaley1 double precision skewx1 double precision skewy1 double precision ulx2 double precision uly2 double precision scalex2 double precision scaley2 double precision skewx2 double precision skewy2 boolean ST_SameAlignment raster set rastfield Non-Aggregate version (Variants 1 and 2): Returns true if the two rasters (either provided directly or made using the values for upperleft, scale, skew and srid) have the same scale, skew, srid and at least one of any of the four corners of any pixel of one raster falls on any corner of the grid of the other raster. Returns false if they don't and a NOTICE detailing the alignment issue. Aggregate version (Variant 3): From a set of rasters, returns true if all rasters in the set are aligned. The ST_SameAlignment() function is an "aggregate" function in the terminology of PostgreSQL. That means that it operates on rows of data, in the same way the SUM() and AVG() functions do. Availability: 2.0.0 Enhanced: 2.1.0 addition of Aggegrate variant SELECT ST_SameAlignment( ST_MakeEmptyRaster(1, 1, 0, 0, 1, 1, 0, 0), ST_MakeEmptyRaster(1, 1, 0, 0, 1, 1, 0, 0) ) as sm; sm ---- t SELECT ST_SameAlignment(A.rast,b.rast) FROM dummy_rast AS A CROSS JOIN dummy_rast AS B; NOTICE: The two rasters provided have different SRIDs NOTICE: The two rasters provided have different SRIDs st_samealignment ------------------ t f f f , , ST_NotSameAlignmentReason Returns text stating if rasters are aligned and if not aligned, a reason why. text ST_NotSameAlignmentReason raster rastA raster rastB Returns text stating if rasters are aligned and if not aligned, a reason why. If there are several reasons why the rasters are not aligned, only one reason (the first test to fail) will be returned. Availability: 2.1.0 SELECT ST_SameAlignment( ST_MakeEmptyRaster(1, 1, 0, 0, 1, 1, 0, 0), ST_MakeEmptyRaster(1, 1, 0, 0, 1.1, 1.1, 0, 0) ), ST_NotSameAlignmentReason( ST_MakeEmptyRaster(1, 1, 0, 0, 1, 1, 0, 0), ST_MakeEmptyRaster(1, 1, 0, 0, 1.1, 1.1, 0, 0) ) ; st_samealignment | st_notsamealignmentreason ------------------+------------------------------------------------- f | The rasters have different scales on the X axis (1 row) , ST_Within Return true if no points of raster rastA lie in the exterior of raster rastB and at least one point of the interior of rastA lies in the interior of rastB. boolean ST_Within raster rastA integer nbandA raster rastB integer nbandB boolean ST_Within raster rastA raster rastB Raster rastA is within rastB if and only if no points of rastA lie in the exterior of rastB and at least one point of the interior of rastA lies in the interior of rastB. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. This operand will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_Within(ST_Polygon(raster), geometry) or ST_Within(geometry, ST_Polygon(raster)). ST_Within() is the inverse of ST_Contains(). So, ST_Within(rastA, rastB) implies ST_Contains(rastB, rastA). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_Within(r1.rast, 1, r2.rast, 1) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_within -----+-----+----------- 2 | 1 | f 2 | 2 | t , , , ST_DWithin Return true if rasters rastA and rastB are within the specified distance of each other. boolean ST_DWithin raster rastA integer nbandA raster rastB integer nbandB double precision distance_of_srid boolean ST_DWithin raster rastA raster rastB double precision distance_of_srid Return true if rasters rastA and rastB are within the specified distance of each other. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. The distance is specified in units defined by the spatial reference system of the rasters. For this function to make sense, the source rasters must both be of the same coordinate projection, having the same SRID. This operand will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_DWithin(ST_Polygon(raster), geometry). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_DWithin(r1.rast, 1, r2.rast, 1, 3.14) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_dwithin -----+-----+------------ 2 | 1 | f 2 | 2 | t , ST_DFullyWithin Return true if rasters rastA and rastB are fully within the specified distance of each other. boolean ST_DFullyWithin raster rastA integer nbandA raster rastB integer nbandB double precision distance_of_srid boolean ST_DFullyWithin raster rastA raster rastB double precision distance_of_srid Return true if rasters rastA and rastB are fully within the specified distance of each other. If the band number is not provided (or set to NULL), only the convex hull of the raster is considered in the test. If the band number is provided, only those pixels with value (not NODATA) are considered in the test. The distance is specified in units defined by the spatial reference system of the rasters. For this function to make sense, the source rasters must both be of the same coordinate projection, having the same SRID. This operand will make use of any indexes that may be available on the rasters. To test the spatial relationship of a raster and a geometry, use ST_Polygon on the raster, e.g. ST_DFullyWithin(ST_Polygon(raster), geometry). Availability: 2.1.0 SELECT r1.rid, r2.rid, ST_DFullyWithin(r1.rast, 1, r2.rast, 1, 3.14) FROM dummy_rast r1 CROSS JOIN dummy_rast r2 WHERE r1.rid = 2; rid | rid | st_dfullywithin -----+-----+----------------- 2 | 1 | f 2 | 2 | t ,