object reduce(int colors) object reduce_fs(int colors)
reduces the number of colors
All needed (see create ) colors are kept.
reduce_fs creates and keeps the outmost corners of the color space, to improve floyd-steinberg dithering result. (It doesn't work very well, though.)
target number of colors
the new Colortable object
this algorithm assumes all colors are different to begin with (!)
reduce_fs keeps the "corners" as "needed colors".
corners