One option in
Corel Photo-Paint is
Image >
Transform >
Posterize.
Posterize isn't listed in my
American Heritage College Dictionary, nor could I find a definition at
Merriam-Webster Online. But here's what it can do:



Corel Photo-Paint
Help says that
posterize allows the user to "reduce the number of tonal values in an image to remove gradations and create larger areas of flat color."
Whatever! I just say
cool.