An integrated approach for high-compression of videoconference sequences

We propose a system for very low bit rate video transmission, leading to good quality images with 200:1 compression ratios. The algorithm first locates the head of the speaker using active snakes. A new form of internal energy is defined allowing a robust and fast head tracking. The most important face characteristics are extracted using a new algorithm. Fractional pixel block matching is used for motion estimation and compensation. The compensated difference image is decomposed in different psicovisual importance areas that are independently processed. The areas are segmented into regions the borders of which are coded using a differential chain code