The information on this page is OUTDATED. The Quality of the dithering in the Gimp has improved vastly and the plugin no longer works for Gimp 2.x.

Floyd-Steinberg Dithering for the GIMP

Lets face it: The builtin Floyd Steinberg dithering of gimp is ugly (I think, there is an error in the implementation). I wrote a small plugin for a better dithering.

The plugin is not a complete replacement for the builtin dithering, since it can not dither against a given colormap. But dithering to Black/White or the Web-optimized palette gives better results than the builtin:

Screenshot

Original Original Image
Gimp's dithering Gimp's builtin dithering
(no joke...)
F-S Dithering Floyd-Steinberg Dithering

To dither to the Web216-Palette select all channels and select 6 shades:

Original Gimp's dithering F-S Dithering
Original Image Gimp's builtin dithering Floyd-Steinberg Dithering

It is also possible to dither the alpha-channel. Not a PNG-Replacement, but possibly useful.

A picture
The same picture
Guess what? The same picture ;-)

I consider this plugin as stable.

OK. Here is the code fsdither.c.

Any suggestions (or bugfixes!!!! :-) to Simon Budig

Have Fun.

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