This is basically just a laundry list of computer vision related resources.
Open source c and c++ libraries for computer vision related projects. Over 500 different algorithms available.
The Augmented Reality Tool Kit (ARToolKit) captures images from video sources, optically tracks markers in the images, and composites them with computer-generated content using OpenGL.
A computer vision library for detection and pose estimation of 2D fiducial markers. Studierstube Tracker was developed with mobile phones in mind.
A webcam image processing library on top of OpenCV intended to generate events from user's head, hand and body movements.
Pose estimation for 3D objects using OpenCV.