Android Question Collision detection with bitmap

[gma]

Hi,

after a lot of search without any result I need to start a thread with the following:
imagine that I have a bitmap, which contains random sharp edges, colors are reduced to be separated by the background, which happens to be quite homogenic.
Now I would like to obtain some collision detection somehow, preferably in an opengl accelerated surface.
What is the ideal method for this?

For an example, I would say I want some functionality as seen in those "Sandbox" type android games.

Thanks.