Jmol GIF color comparison

Comparision of Jmol 14.3.9 GIF 256-color rendering of image with 25957 colors originally with a previous version of Jmol, with GIMP, and with a full-color PNG image. This comparison documents the successful use of Floyd-Steinberg color dithering along with center-cut (not median-cut) color quantization in L*a*b color space. Jmol 14.3.9 is on the left in each case. -- Bob Hanson hansonr@stolaf.edu

Jmol 14.3.9 GIF (64KB) vs. Jmol 14.0.17 GIF (52KB)
Older versions of Jmol just threw out the lesser-used colors with no dithering.

Jmol 14.3.9 GIF (64KB) vs. GIMP GIF Floyd-Steinberg normal (81KB)
Jmol is very close to GIMP in quality -- perhaps better? The blue atom looks better to me.

A close up of that atom shows the difference. Note that Jmol does not dither into the background color, producing a cleaner outline.
Jmol 14.3.9 GIF (64KB) vs. GIMP GIF Floyd-Steinberg reduced color bleed (81KB)
It is not clear that reduced color bleed in GIMP does much better in this case.

Jmol 14.3.9 GIF (64KB) vs. PNG (25957 colors, 240KB)
The difference between 256 colors with dithering and 26,000 colors without. Note the 73% size savings.