Code: Select all
convert input.png -dither Riemersma -remap palette.png -colors 15 output.png
Input is an arbitrary image. Palette looks like this: http://topolla.net/images/palette.png
A two step process like this works, but I don't think it chooses the best image.
Code: Select all
convert input.png -dither Riemersma -remap palette.png ouput.png
convert ouput.png -dither Riemersma -colors 15 ouput_final.png