<_welcome>
Welcome to The GIMP !
<_thetip>
Nearly all image operations are performed by right-clicking
on the image. And don't worry, you can undo most mistakes...
<_thetip>
You can get context-sensitive help for most of the GIMP's features by
pressing the F1 key at any time. This also works inside the menus.
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The GIMP uses layers to let you organize your image. Think of them
as a stack of slides or filters, such that looking through them you
see a composite of their contents.
<_thetip>
You can perform many layer operations by right-clicking on the text
label of a layer in the Layers dialog.
<_thetip>
When you save an image to work on it again later, try using XCF,
the GIMP's native file format (use the file extension .xcf).
This preserves the layers and every aspect of your work-in-progress.
Once a project is completed, you can save it as JPEG, PNG, GIF, ...
<_thetip>
The layer named "Background" is special because it lacks
transparency. This prevents you from adding a layer mask or moving
the layer up in the stack. You may add transparency to it by
right-clicking in the Layers dialog and selecting
"Add Alpha Channel".
<_thetip>
Most plug-ins work on the current layer of the current image. In
some cases, you will have to merge all layers (Image->Flatten Image)
if you want the plug-in to work on the whole image.
<_thetip>
Not all effects can be applied to all kinds of images. This is
indicated by a grayed-out menu-entry. You may need to change
the image mode to RGB (Image->Mode->RGB), add an alpha-channel
(Layers->Transparency->Add Alpha Channel) or flatten it
(Image->Flatten Image).
<_thetip>
You can drag and drop many things in the GIMP. For example, dragging
a color from the toolbox or from a color palette and dropping it into
an image will fill the current image or selection with that color.
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When using a drawing tool (Paintbrush, Airbrush, or Pencil),
Shift-click will draw a straight line from your last drawing
point to your current cursor position. If you also press Ctrl,
the line will be constrained to 15 degree angles.
<_thetip>
The file selection dialog box has command-line completion with
Tab, just like the shell. Type part of a filename, hit
Tab, and voila, it's completed.
<_thetip>
You can use the middle mouse button to pan around the image, if it's
larger than its display window.
<_thetip>
Click and drag on a ruler to place a Guide on an image. All
dragged selections will snap to the guides. You can remove
guides by dragging them off the image with the Move tool.
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You can drag a layer from the Layers dialog and drop it onto the
toolbox. This will create a new image containing only that layer.
<_thetip>
A Floating Selection must be anchored to a new layer or to the last
active layer before doing other operations on the image. Click on the
"New Layer" or "Anchor Layer buttons" in the Layers
dialog, or use the menus to do the same.
<_thetip>
The GIMP supports gzip compression on the fly. Just add .gz
(or .bz2, if you have bzip2 installed) to the filename and
your image will be saved compressed. Of course loading compressed
images works too.
<_thetip>
Pressing and holding the Shift key before making a selection
allows you to add to the current selection instead of replacing it.
Using Ctrl before making a selection subtracts from the
current one.
<_thetip>
You can press or release the Shift and Ctrl keys
while you are making a selection in order to constrain it to a perfect
square or circle, or to have it centered on its starting point.
<_thetip>
You can adjust and re-place a selection by using Alt-drag.
If this makes the window move, your window manager uses the
Alt key already. Try pressing Shift at the same
time.
<_thetip>
You can draw simple squares or circles using Edit->Stroke Selection.
It strokes the edge of your current selection. More complex shapes
can be drawn using the Path tool or with Filters->Render->Gfig.
<_thetip>
If you stroke a path (Edit->Stroke Path), the paint tools can
be used with their current settings. You can use the Paintbrush in
gradient mode or even the Eraser or the Smudge tool.
<_thetip>
You can create and edit complex selections using the Path tool.
The Paths dialog allows you to work on multiple paths and to convert
them to selections.
<_thetip>
You can use the paint tools to change the selection. Click on the
"Quick Mask" button at the bottom left of an image window.
Change your selection by painting in the image and click on the button
again to convert it back to a normal selection.
<_thetip>
You can save a selection to a channel (Select->Save to Channel) and
then modify this channel with any paint tools. Using the buttons in
the Channels dialog, you can toggle the visibility of this new channel
or convert it to a selection.
<_thetip>
After you enabled "Dynamic Keyboard Shortcuts" in the
Preferences dialog, you can reassign shortcut keys. Do so by bringing
up the menu, selecting a menu item, and pressing the desired key
combination. If "Save Keyboard Shortcuts" is enabled, the
key bindings are saved when you exit GIMP.
<_thetip>
If your screen is too cluttered, you can press Tab multiple
times in an image window to hide or show the toolbox and other dialogs.
<_thetip>
You can adjust the selection range for fuzzy select
by clicking and dragging left and right.
<_thetip>
Shift-click on the eye icon in the Layers dialog to hide all
layers but that one. Shift-click again to show all layers.
<_thetip>
Ctrl-click on the layer mask's preview in the Layers dialog
toggles the effect of the layer mask.
<_thetip>
Alt-click on the layer mask's preview in the Layers dialog
toggles viewing the mask directly.
<_thetip>
You can use Alt-Tab to cycle through all layers in
an image (if your window manager doesn't trap those keys...).
<_thetip>
Ctrl-click with the Bucket Fill tool to have it use
the background color instead of the foreground color.
<_thetip>
Ctrl-drag with the Rotate tool will constrain the
rotation to 15 degree angles.
<_thetip>
To create a perfect circle, hold Shift while doing an
ellipse select. To place a circle precisely, drag horizontal and
vertical guides tangent to the circle you want to select, place
your cursor at the intersection of the guides, and the resulting
selection will just touch the guides.
<_thetip>
If some of your scanned photos do not look colorful enough, you can
easily improve their tonal range with the "Auto" button in the
Levels tool (Layer->Colors->Levels). If there are any color casts,
you can correct them with the Curves tool (Layer->Colors->Curves).