This is the homepage of the Shape Contexts based approach to break Gimpy, the CAPTCHA test used at Yahoo! to screen out bots. This method can successfully pass that test 92% of the time. See EZ-Gimpy in action at Yahoo! The approach this soft take uses general purpose algorithms that have been designed for generic object recognition. The same basic ideas have been applied to finding people in images, matching handwritten digits, and recognizing 3D objects.

http://www.cs.sfu.ca/~mori/research/gimpy/