A feature‐based approach to facial expression cloning

In this paper, we present a feature‐based approach to cloning facial expressions from an input face model to an output model, using predefined source key‐models and the corresponding target key‐models. Adopting a scattered data interpolation technique, our approach consists of two parts: analysis of face key‐models and synthesis of facial expressions. In the analysis part carried out once at the beginning, key‐models are segmented automatically into five regions, each containing one of five facial features, that is, eyes, cheeks, and the mouth, which give rise to five sets of source key‐shapes and the corresponding sets of target key‐shapes. Using the key‐shapes of each source feature, those of the corresponding target feature are parameterized. In the synthesis part, given a sequence of face models comprising an input animation, five output features are obtained separately by blending their own target key‐shapes. These separately produced features are combined to synthesize the output face model at each frame. Our feature‐based approach enables cloning of diverse expressions including asymmetric ones convincingly with a small number of face key‐models while exhibiting an on‐line, real‐time performance.