Posterization is a process wherein gradients are replaced by regions of solid tonal average. You know, like a poster. It's like color banding only it's done on purpose and looks cool. Since a lot of anime stuff is pretty close to that anyway, add it here only if it's a very reduced palette. For now, please leave straight two-color images out, however. As a general rule of thumb, if it looks like it could easily be made with pieces of colored paper, add it.
