Problem
You want to create a favicon.ico from Unix.
Solution
- Open your image with GIMP
- If your image is not a square then resize the canvas with GIMP
- Scale the image to 16×16 pixel (Image, Scale image)
- Save as favicon.pnm or favicon.ppm with raw encoding
- Close GIMP
Example
Then to convert favicon.pnm or favicon.ppm using the command line utility ppmtowinicon:
$ ppmtowinicon -output favicon.ico favicon.pnm
Or
$ ppmtowinicon -output favicon.ico favicon.ppm
Reference
Kewl tip on creating a favicon.ico with ppmtowinico – thanks to linuxproblem.org. 🙂