Animating facial expressions

Recognition and simulation of actions performable on rigidly-jointed actors such as human bodies have been the subject of our research for some time. One part of an ongoing effort towards a total human movement simulator is to develop a system to perform the actions of American Sign Language (ASL). However, one of the “channels” of ASL communication, the face, presents problems which are not well handled by a rigid model. An integrated system for an internal representation and simulation of the face is presented, along with a proposed image analysis model. Results from an implementation of the internal model and simulation modules are presented, as well as comments on the future of computer controlled recognition of facial actions. We conclude with a discussion on extensions of the system, covering relations between flexible masses and rigid (jointed) ones. Applications of this theory into constrained actions, such as across rigid nonmoving sheets of bone (forehead, eyes) are also discussed.