Real-time 2½D head pose recovery for model-based video-coding

This paper discusses a 2½D tracking method allowing real-time recovery of the 3D position and orientation of a head moving in its image plane. The described method uses a 2D elliptical head model, region- and edge-based matching algorithms, and a linear Kalman filter estimation. The resulting motion tracking system works in a realistic environment without makeup on the face, with uncalibrated camera and unknown lighting conditions and background