A feature I enjoyed way back in paintshop pro was that you could split the HSV or RGB values of an image into three different images, edit them and then recombine.
With for instance a person in front of a wall, I could copy a section of the wall in the hue and saturation images, paste it onto the person's clothes and get a nice effect where the clothes were blending in with the background, as if by camouflage.
Now I could of course adjust the hue and saturation of the clothes directly, but the way I remember it, copy and paste gave a better result because it retained the "texture" of the hue and saturation components. (or so I seem to recall)
Maybe this could be an idea for a plugin, or maybe you could accomplish the same thing using the existing tools in Paint.Net?
