GIMP Usage
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Interface
- If you run the GIMP under KDE, start it in a new desktop: that's currently the only way I found to get all the GIMP windows to reappear when working with multiple applications.
- All tools have simple key shortcuts that are very useful, try to remember them.
Saving
- PNG format allows you to choose the compression level. The default maximal compression level acts strangely (artifacts on the image), so if that happens reduce the compression level to 5-6.
Selection
- When making a selection, for example with the rectangle tool, you have to confirm it by clicking on it. Until this click, the selection is easily modifiable by using the sub-rectangles appearing
- A selection also usually shows the layer boundaries (which is a good thing).
- You can create a new selection based on a layer "contents" (parts that are not transparent). This is done by right-clicking on the layer and choosing "Alpha to selection".
- If you create a anti-aliased selection, this will apply to future operations. For example, a fill on an anti aliased rectangle will not fill uniformly the rectangle with the color; the edges will get a smooth transition.
Scripting
- Scripting the GIMP can be done easily using the Python API. You can write pure Python scripts, and you don't need to use Scheme at all.
- In order to make your Python script accessible from within the GIMP, you need to save it in ~/.gimp-2.4/plug-ins/. You need to make it executable or GIMP won't recognize it.
- In your script, you need to have the register() function and a main() function which can be empty, in addition to your actual function which executes what you want. Here are the arguments for the register function (with an example):
- "generate_rounded_corners": Name of the plugin (how to call it programmatically with Script-Fu)
- "This is a test Python plugin." : Textual description
- "It creates and saves an image.": Other description (extended, not sure here)
- "Elvanör": Author
- "Jean-Noël Rivasseau": Copyright owner
- "2007": Date
- "_Rounded Corners...": Name of the plugin (in the GIMP menus)
- "RGB*, GRAY*": Modes accepted (??)
- []: Arguments to this plugin
- []: Return values of this plugin, only useful in non interactive mode
- generateRoundedCorners: Python callback function (essential!)
- menu="<Image>/Filters/Render/Rounder Corners": Path in the menus
- In the previous list, the arguments list has the following syntax:
- PF_STRING: type of argument
- "targetDirectory": argument name
- "The directory in which will be saved the images": description
- "/srv/": Default value. This is used *only* in the interface, eg. when using the plugin non interactively you must always pass the correct number of arguments.
- The _() function that you can see used in example plug-ins is for internationalization. The "_R" in "_Rounded Corners..." is for the mnemonic, eg the key that will be associated as a shortcut in the interface.