This paper discusses a 2(1/2)-D tracking method allowing real-time recovery
of the three-dimensional (3-D) position and orientation of a head moving i
n its image plane. The described method uses a two-dimensional (2-D) ellipt
ical head model, region- and edge-based matching algorithms, and a linear K
alman filter estimator. The resulting motion tracking system works in a rea
listic environment without makeup on the face, with an uncalibrated camera,
normal lighting conditions, and an unknown background.