gifgthumbimage processing
I edited a GIF image (no animations) with gthumb and on trying to save I encountered the error:
Could not save the file
Could not find a suitable module to save the image as "image/gif"
I jumped over to the preferences only to find save as GIF isn't there. Only JPG, PNG, TIFF, TGA, WebP.
Is there any way I can save an image as GIF from gthumb without converting it to the other formats?
Warning: broken. Shutter is severely broken in Ubuntu 18.04 and not available in later versions.
Shutter (which you can install from the Ubuntu Software Centre or sudo apt-get install shutter) is a tool which has a variety of options for taking and annotating screenshots. (Note: You can annotate any images of your choice, not just screenshots.)
ImageOptim uses Gifsicle for its Gif compression. As far as I know, it works quite well (I don't generally use Gif these days). From their site:
Optimize your animations! This stores only the changed portion of each frame, and can radically shrink your GIFs. You can also use transparency to make them even smaller. Gifsicle’s optimizer is pretty powerful, and usually reduces animations to within a couple bytes of the best commercial optimizers.
Best Answer
All of the Gthumb docs don't list GIF in the supported formats for saving. The more specialized program GIMP will do it.