A hybrid codec for very low bit rate video coding

In segmentation based video compression algorithms, the quality of the segmentation and the efficiency of the boundary coding have strong influence on the coding efficiency and image quality. We propose a hybrid codec using motion segmentation and employing a variable size block structure. The image is segmented based on motion and grey level information and represented by variable size blocks combined with an inner block partition. A method of partitioning using fixed patterns is developed to encode the motion boundaries inside a block. This approach improves the boundary coding efficiency by a factor of three as compared with the straight line approximation used in our earlier approach. The experimental results show that the proposed algorithm decreases the bit rate and preserves good image quality.