Realistic facial animation is one of the most fundamental problems in computer graphics. The applications of facial animation are very diverse, and include fields that range from purely recreational to life enhancing. Perhaps the best known application of facial animation is in the film industry. Their systems are traditionally based on keyframe animation, with many parameters that influence the appearance of the face. Another application of facial animation is computer games, where titles such as Full Throttle and The Curse of Monkey Island used facial animation for their 2D cartoon characters. This trend continued into 3D titles, where games such as Tomb Raider and Grim Fandango used facial animation as the key tool to communicate the story to the player.
Description of Facial Animation
Facial animation is also being applied in medical fields like facial surgery planning and previewing the effects of dental surgery. However, these pre-operative applications would require a very accurate anatomical model of the patient's face. This is not very practical, because each face varies enormously from the next, and acquiring face data can be tedious Facial Animation can also be used as a teaching aid. Talking Tiles is an application of Hyper Animation that aids with the teaching of language skills. Facial animation could also be used to teach the hearing impaired. A face model could demonstrate how certain words are pronounced, while cut-away views show where the tongue needs to be positioned to create the desired sounds.
The important issue to remember is that all these varied applications, film, computer games, medicine and teaching, use facial animation as a communications medium. That is, they utilise a
computer simulation of a human face in order to reach the audience more convincingly.
The MPEG-4 standard provides a set of technologies to satisfy the needs of authors, service providers and end users alike.· For authors, MPEG-4 enables the production of content that has far greater reusability, has greater flexibility than is possible today with individual technologies such as digital television, animated graphics, World Wide Web (WWW) pages and their extensions. Also, it is now possible to better manage and protect content owner rights.
For network service providers MPEG-4 offers transparent information, which can be interpreted and translated into the appropriate native signalling messages of each network with the help of relevant standards bodies. The foregoing, however, excludes Quality of Service considerations, for which MPEG-4 provides a generic QoS descriptor for different MPEG-4 media. The exact translations from the QoS parameters set for each media to the network QoS are beyond the scope of MPEG-4 and are left to network providers. Signaling of the MPEG-4 media QoS descriptors end-to-end enables transport optimization in heterogeneous networks.