The most useful name for Floyd-Steinberg is 'error diffusion'.. it's based on the idea of diffusing color error across spatially adjacent pixels. Of course, that is the essential effect of all dithering, but the salient point is that it is individual-pixel-based and so probably isn't useful or easily reproduceable for pixel artists.
Here is an example which might show you why:
Personally, I find it.. prickly and annoying.
Floyd-Steinberg is indeed one of the most commonly used dithering methods in paint programs. The other method is positional dithering, which is based on a dither matrix.
Positional dithering works like this (simplified code):
' dist is the position of this color on the imaginary range between available colors A and B, ranging 0..255
' calculate the coordinates of this point in the dither matrix
mx = x MODULUS dithermatrix_w
my = y MODULUS dithermatrix_h
a_or_b = matrix
if a_or_b > dist:
finalpixelcolor = colorB
else:
finalpixelcolor = colorA
Positional dithering is usually done using a Bayer matrix, 16x16 or bigger.
If other choices than those two are presented, they may just be positional dithers with alternate matrices (for instance, dithering for print works differently to dithering for screen display). A number of the ones I posted were done by reconfiguring GIMP's positional dithering to use alternate matrices.
Most dithering methods used in pixel art are primarily positional.
Exceptions mentioned in this thread are style dither and messy diagonal block dither, which are both based on the principle of error diffusion.
« Last Edit: September 28, 2006, 10:53:59 am by Ai »
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If you insist on being pessimistic about your own abilities, consider also being pessimistic about the accuracy of that pessimistic judgement.
