2.3. Images
You also have to manage screenshots. Here are some hints for making good screenshots:
reduce screenshot area as much as possible cropping the window manager borders and disabling the help button (you can do it in the preference dialog),
set the image mode to indexed 255 colors Image → Mode → Indexed
This is not necessary for icons and if your image has only few colors. In these cases, indexed images are bigger than non-indexed.
set print resolution to 144 ppi (not for small images like icons). You can do this easily with GIMP from Image → Print Size…
Export images in the PNG format.
Don’t include English text in images. Translators can’t translate it and many users don’t like that. Use XML captions instead, or provide a .xcf file in the Docs → xcf images folder, indicating it by a comment in the XML file:
Icons for GIMP are in usr/share/gimp/2.0/icons. GTK icons are in usr/share/gtk-doc/html/gtk2.
To include an icon in the text:
Three commands to manage your images:
make check-image-resolutions-en: gives the references of images whose resolution is not 144 ppi.
make check-images-en: give references of missing or orphaned images.
mogrify units PixelsPerTrack -density 144x144 *.png to set the print resolution of all PNG images.