You can do that -or- create an approximation of polygonal regions which are tested against simple collision shapes likes circles or rectangles. I shouldn't have said "polygonal" regions, because you might think I'm talking about meshes.. I talk only about a datamodel of it for calculations.

If you have this, you move your collision shape and if it intersects with an edge of a region, it collides - bingo!.. *stop moving*. To test if a shape collides you can test certain (or special) contact points per shape. This is non-trivial to beginners, because you have to basic knowledge about vector geometry and planes & lines in particular. Though, you can make a polygonal shape around your sprite and test this agains the environment shape.. then you have pixel precision.

To simplify it, DirectX has (through Lite-C) a lot of functions for this kind of stuff to quickly make a prototype... well, this is how I would try it.

I think if you google for "pixel based collision" or something like that you will get some articles, on gamedev.net (I think) there are some.