Legacy ImageMagick Discussions Archive

IM 6.8.1.10 Q16 Mac OSX Snow Leopard.

Using the example colorwheel.png image at http://www.imagemagick.org/Usage/quantize/#posterize, I see no difference with dither on or off with these commands


convert colorwheel.png +dither -posterize 3 show:
convert colorwheel.png -dither Riemersma -posterize 3 show:
convert colorwheel.png -dither FloydSteinberg -posterize 3 show:
convert colorwheel.png -posterize 3 show:

Is this a bug or am I missing something?

Dither does not work with posterize. I have no idea why, I reported it years ago.