Automatic wire-frame fitting and automatic wire-frame tracking are the two
most important and most difficult issues associated with semantic-based mov
ing image coding. A novel approach to high speed tracking of important faci
al features is presented as a part of a complete fitting-tracking system. T
he method allows real-time processing of head-and-shoulders sequences using
software tools only. The algorithm is based on eigenvalue decomposition of
the sub-images extracted from subsequent frames of the video sequence. Eac
h important facial feature (the left eye, the right eye, the nose and the l
ips) is tracked separately using the same method. The algorithm was tested
on widely used head-and-shoulders video sequences containing the speaker's
head pan, rotation and zoom with remarkably good results. These experiments
prove that it is possible to maintain tracking even when the facial featur
es are partially occluded. (C) 2000 Academic Press.