TDA: A new trainable trajectory formation system for facial animation

Overview & Synopsis

A new trainable trajectory formation system - named TDA - for facial animation is here proposed that dissociates parametric spaces and methods for movement planning and execution. Movement planning is achieved by HMM-based trajectory formation. This module essentially plans configurations of lip geometry (aperture, spreading and protrusion). Movement execution is performed by concatenation of multi-represented diphones. This module is responsible for selecting and concatenating detailed facial movements that best obey to the target kinematics of the geometry previously planned. Movement planning ensures that the essential visual characteristics of visemes are reached (lip closing for bilabials, rounding and opening for palatal fricatives, etc) and that appropriate coarticulation is planned. Movement execution grafts phonetic details and idiosyncratic articulatory strategies (dissymetries, importance of jaw movements, etc) to the planned gestural score. This planning scheme is compared to alternative planning strategies using articulatory modeling and motion capture data