gimp/plug-ins/common/laplace.c

342 lines
9.6 KiB
C

/* The GIMP -- an image manipulation program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* This plugin by thorsten@arch.usyd.edu.au */
/* Based on S&P's Gauss and Laplace filters */
/* updated 11/04/97:
Use 8-pixel neighbourhood to create outline,
use min-max operation for local gradient,
don't use rint;
if gamma-channel: set to white if at least one colour channel is >15 */
/* update 03/10/97
#ifdef MAX and MIN */
#include <stdlib.h>
#include "libgimp/gimp.h"
#include <stdio.h>
#include <math.h>
/* Declare local functions.
*/
static void query (void);
static void run (char *name,
int nparams,
GParam *param,
int *nreturn_vals,
GParam **return_vals);
static void laplace (GDrawable *drawable);
static void laplace_prepare_row (GPixelRgn *pixel_rgn,
guchar *data,
int x,
int y,
int w);
GPlugInInfo PLUG_IN_INFO =
{
NULL, /* init_proc */
NULL, /* quit_proc */
query, /* query_proc */
run, /* run_proc */
};
MAIN ()
static void
query ()
{
static GParamDef args[] =
{
{ PARAM_INT32, "run_mode", "Interactive, non-interactive" },
{ PARAM_IMAGE, "image", "Input image (unused)" },
{ PARAM_DRAWABLE, "drawable", "Input drawable" },
};
static GParamDef *return_vals = NULL;
static int nargs = sizeof (args) / sizeof (args[0]);
static int nreturn_vals = 0;
gimp_install_procedure ("plug_in_laplace",
"Edge Detection with Laplace Operation",
"This plugin creates one-pixel wide edges from the image, with the value proportional to the gradient. It uses the Laplace operator (a 3x3 kernel with -8 in the middle)The image has to be laplacered to get usefull results, a gauss_iir with 1.5 - 5.0 depending on the noise in the image is best",
"Thorsten Schnier",
"Thorsten Schnier",
"1997",
"<Image>/Filters/Edge-Detect/Laplace",
"RGB*, GRAY*",
PROC_PLUG_IN,
nargs, nreturn_vals,
args, return_vals);
}
static void
run (char *name,
int nparams,
GParam *param,
int *nreturn_vals,
GParam **return_vals)
{
static GParam values[1];
GDrawable *drawable;
GRunModeType run_mode;
GStatusType status = STATUS_SUCCESS;
run_mode = param[0].data.d_int32;
/* Get the specified drawable */
drawable = gimp_drawable_get (param[2].data.d_drawable);
/* Make sure that the drawable is gray or RGB color */
if (gimp_drawable_color (drawable->id) || gimp_drawable_gray (drawable->id))
{
gimp_tile_cache_ntiles (2 * (drawable->width / gimp_tile_width () + 1));
laplace (drawable);
if (run_mode != RUN_NONINTERACTIVE)
gimp_displays_flush ();
}
else
{
/* gimp_message ("laplace: cannot operate on indexed color images"); */
status = STATUS_EXECUTION_ERROR;
}
*nreturn_vals = 1;
*return_vals = values;
values[0].type = PARAM_STATUS;
values[0].data.d_status = status;
gimp_drawable_detach (drawable);
}
static void
laplace_prepare_row (GPixelRgn *pixel_rgn,
guchar *data,
int x,
int y,
int w)
{
int b;
if (y == 0)
gimp_pixel_rgn_get_row (pixel_rgn, data, x, (y + 1), w);
else if (y == pixel_rgn->h)
gimp_pixel_rgn_get_row (pixel_rgn, data, x, (y - 1), w);
else
gimp_pixel_rgn_get_row (pixel_rgn, data, x, y, w);
/* Fill in edge pixels */
for (b = 0; b < pixel_rgn->bpp; b++)
{
data[-(int)pixel_rgn->bpp + b] = data[b];
data[w * pixel_rgn->bpp + b] = data[(w - 1) * pixel_rgn->bpp + b];
}
}
#define SIGN(a) (((a) > 0) ? 1 : -1)
#define RMS(a,b) (sqrt (pow ((a),2) + pow ((b), 2)))
#ifndef MAX
#define MAX(a,b) (((a) > (b)) ? (a) : (b))
#endif
#ifndef MIN
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif
#define BLACK_REGION(val) ((val) > 128)
#define WHITE_REGION(val) ((val) <= 128)
static void minmax (gint x1, gint x2, gint x3, gint x4, gint x5,
gint* min_result, gint* max_result)
{
gint min1,min2,max1,max2;
if (x1>x2) {max1=x1; min1=x2;} else {max1=x2; min1=x1;}
if (x3>x4) {max2=x3; min2=x4;} else {max2=x4; min2=x3;}
if (min1<min2)
*min_result = MIN (min1, x5);
else *min_result = MIN (min2, x5);
if (max1>max2)
*max_result = MAX (max1, x5);
else *max_result = MAX (max2, x5);
}
static void
laplace (GDrawable *drawable)
{
GPixelRgn srcPR, destPR;
gint width, height;
gint bytes;
gint current;
gint gradient;
gint max_gradient = 0;
gint alpha;
gint counter;
guchar *dest, *d;
guchar *prev_row, *pr;
guchar *cur_row, *cr;
guchar *next_row, *nr;
guchar *tmp;
gint row, col;
gint x1, y1, x2, y2;
gint minval, maxval;
float scale = 1.0;
/* Get the input area. This is the bounding box of the selection in
* the image (or the entire image if there is no selection). Only
* operating on the input area is simply an optimization. It doesn't
* need to be done for correct operation. (It simply makes it go
* faster, since fewer pixels need to be operated on).
*/
gimp_drawable_mask_bounds (drawable->id, &x1, &y1, &x2, &y2);
gimp_progress_init ("Laplace");
/* Get the size of the input image. (This will/must be the same
* as the size of the output image.
*/
width = drawable->width;
height = drawable->height;
bytes = drawable->bpp;
alpha = gimp_drawable_has_alpha (drawable -> id);
/* allocate row buffers */
prev_row = (guchar *) malloc ((x2 - x1 + 2) * bytes);
cur_row = (guchar *) malloc ((x2 - x1 + 2) * bytes);
next_row = (guchar *) malloc ((x2 - x1 + 2) * bytes);
dest = (guchar *) malloc ((x2 - x1) * bytes);
/* initialize the pixel regions */
gimp_pixel_rgn_init (&srcPR, drawable, 0, 0, width, height, FALSE, FALSE);
gimp_pixel_rgn_init (&destPR, drawable, 0, 0, width, height, TRUE, TRUE);
pr = prev_row + bytes;
cr = cur_row + bytes;
nr = next_row + bytes;
laplace_prepare_row (&srcPR, pr, x1, y1 - 1, (x2 - x1));
laplace_prepare_row (&srcPR, cr, x1, y1, (x2 - x1));
/* loop through the rows, applying the laplace convolution */
for (row = y1; row < y2; row++)
{
/* prepare the next row */
laplace_prepare_row (&srcPR, nr, x1, row + 1, (x2 - x1));
d = dest;
for (col = 0; col < (x2 - x1) * bytes; col++)
if (alpha && (((col + 1) % bytes) == 0)) /* the alpha channel */
*d++ = cr[col];
else
{
minmax (pr[col], cr[col - bytes], cr[col], cr[col + bytes],
nr[col], &minval, &maxval); /* four-neighbourhood */
gradient = (0.5 * MIN ((maxval - cr [col]), (cr[col]- minval)));
max_gradient = MAX(abs(gradient), max_gradient);
*d++ = ((pr[col - bytes] + pr[col] + pr[col + bytes] +
cr[col - bytes] - (8 * cr[col]) + cr[col + bytes] +
nr[col - bytes] + nr[col] + nr[col + bytes]) > 0) ?
gradient : (128 + gradient);
}
/* store the dest */
gimp_pixel_rgn_set_row (&destPR, dest, x1, row, (x2 - x1));
/* shuffle the row pointers */
tmp = pr;
pr = cr;
cr = nr;
nr = tmp;
if ((row % 5) == 0)
gimp_progress_update ((double) row / (double) (y2 - y1));
}
/* now clean up: leave only edges, but keep gradient value */
gimp_pixel_rgn_init (&srcPR, drawable, 0, 0, width, height, FALSE, TRUE);
pr = prev_row + bytes;
cr = cur_row + bytes;
nr = next_row + bytes;
laplace_prepare_row (&srcPR, pr, x1, y1 - 1, (x2 - x1));
laplace_prepare_row (&srcPR, cr, x1, y1, (x2 - x1));
gimp_progress_init ("Cleanup");
scale = (255.0 / (float) max_gradient);
counter =0;
/* loop through the rows, applying the laplace convolution */
for (row = y1; row < y2; row++)
{
/* prepare the next row */
laplace_prepare_row (&srcPR, nr, x1, row + 1, (x2 - x1));
d = dest;
for (col = 0; col < (x2 - x1) * bytes; col++) {
current = cr[col];
current = (WHITE_REGION(current) &&
(BLACK_REGION (pr[col - bytes]) ||
BLACK_REGION (pr[col]) ||
BLACK_REGION (pr[col + bytes]) ||
BLACK_REGION (cr[col - bytes]) ||
BLACK_REGION (cr[col + bytes]) ||
BLACK_REGION (nr[col - bytes]) ||
BLACK_REGION (nr[col]) ||
BLACK_REGION (nr[col + bytes]))) ?
(gint) (scale * ((float) ((current >= 128) ?
(current-128) : current)))
: 0;
if (alpha && (((col + 1) % bytes) == 0)) { /* the alpha channel */
*d++ = (counter == 0) ? 0 : 255;
counter = 0; }
else {
*d++ = current;
if (current > 15) counter ++;
}
}
/* store the dest */
gimp_pixel_rgn_set_row (&destPR, dest, x1, row, (x2 - x1));
/* shuffle the row pointers */
tmp = pr;
pr = cr;
cr = nr;
nr = tmp;
if ((row % 5) == 0)
gimp_progress_update ((double) row / (double) (y2 - y1));
}
/* update the laplaced region */
gimp_drawable_flush (drawable);
gimp_drawable_merge_shadow (drawable->id, TRUE);
gimp_drawable_update (drawable->id, x1, y1, (x2 - x1), (y2 - y1));
free (prev_row);
free (cur_row);
free (next_row);
free (dest);
}