Lately I got very interested in image processing. Texture polygonization to be more exact. I know this technique can boost rendering performance when it comes to 2D games, since the program doesn't have to draw as many blank fragments as opposed to drawing the image onto a rectangle. I've seen this method implemented lately in the Unity3D engine.
My question is, can somebody tell me some insights what is the math behind this, and how to get started if I want to learn more about this?
(Sorry for poor english.)