2d(ortho) Pixel detection Collision

Has someone any idea on how to do that?
Do I have to write my own image loader to use arrays to perform collision detection?
Thanks.

The pixels should be pretty accurate. I suggest rendering images also in main memory with custom routines and detecting the images that way. You could look at using the stencil buffer, as well - blit masks to the stencil buffer and do tests with it.