Libccv

http://libccv.org/ One core concept of ccv development is application driven. Thus, ccv ends up implementing a handful state-of-art algorithms. It includes a close to state-of-the-art image classifier, a state-of-the-art frontal face detector, reasonable collection of object detectors for pedestrians and cars, a useful text detection algorithm, a long-term general object tracking algorithm, and the long-standing feature point extraction algorithm.

https://github.com/liuliu/ccv