CoArt: coarticulation region analysis for control of 2D characters

A facial analysis-synthesis framework based on a concise set of local, independently actuated, coarticulation regions (CRs) is presented for the control of 2D animated characters. CRs are parameterized by muscle actuations and thereby provide a physically meaningful description of face state that is easily abstracted to higher-level descriptions of facial expression. An independent component analysis on a set of training images acquired from an actor is used to characterize the appearance space of each CR. Within this framework actor-independent face reconstruction databases can be created by an artist or extracted from video sequences. In addition, the muscle parameter values may be used to drive any similarly parameterized 3D facial model. The flexibility afforded by such a methodology is demonstrated with applications to 2D facial animation control and sample based video synthesis. The analysis runs in real-time on modest consumer hardware.