Knowledge-based Coding of Facial Images based on the Analysis of Feature-Points Motion and Isodensity Lines

In the study of facial motion codings for practical use in TV telephone and TV conference systems, knowledge-based coding has attracted researchers' attention as a concrete example of next-generation image coding schemes[1]-[3]. In such schemes a facial image of a person without any specific expression (the model image) is transmitted over a telephone line, and a wireframe of the face (the model wireframe) is constructed, and stored in the receiving terminal at the beginning of the conversation. During the conversation, movements in the speaker's facial features are measured, and displacements of feature points on the speaker's face are transmitted to the receiving terminal, where the speaker's facial image is reconstructed by transforming the model wireframe according to these data.