Methods and systems for animating facial features, and methods and systems for expression transformation

Abstract

Methods and systems for animating facial features and transforming facial expressions are described. In one embodiment, a code book contains data that defines a set of facial expressions of a first person. A training set of facial expressions from a second person and corresponding expressions from the code book are used to derive a transformation function that is then applied to all of the expressions of the code book. In this manner, expressions from the first person can be realistically transformed into expressions of a second person and vice versa. Particularly advantageous aspects of the described embodiments provide a single common generic face model that is used as the basis for a fitting operation for many different faces. Use of the single common generic face model and certain user-defined constraints provide a mechanism by which correspondences between the different faces can be established. These correspondences provide a basis for facial animation operations, among which are included expression transformation.