Animation of synthetic faces in MPEG-4

MPEG-4 is the first international standard that standardizes true multimedia communication-including natural and synthetic audio, natural and synthetic video, as well as 3D graphics. Integrated into this standard is the capability to define and animate virtual humans consisting of synthetic heads and bodies. For the head, more than 70 model-independent animation parameters defining low-level actions like “move left mouth corner” up to high-level parameters like facial expressions and visemes are standardized In a communication application. The encoder can define the face model using MPEG-4 BIFS (BInary Format for Scenes) and transmit it to the decoder. Alternatively, the encoder can rely on a face model that is available at the decoder. The animation parameters are quantized, predictively encoded using an arithmetic encoder or a DCT. The decoder receives the model and the animation parameters in order to animate the model. Since MPEG-4 defines the minimum MPEG-4 terminal capabilities in profiles and levels, the encoder knows the quality of the animation at the decoder