Hi:
I am a bit late to the party but I may have some answers for you.
There are basically 3 schools of thought regarding stereo matching aka depth map creation from a stereo pair:
1) local method based on window/patch/block correlation
2) global methods like graph cuts
3) variational methods like optical flow
there's no magic method though that works 100% of the time. more often that not, the depth map will have quite a bit of noise depending on how much smoothing has been applied.
I have implemented a fair number of automatic depth map generators that you can try them at:
3D software for depth map creation
the best part is that it's all free to download and use.