Very low bit rate video coding using arbitrarily shaped region-based motion compensation

This paper presents a novel region-based video coding algorithm for very low bit-rate transmission. A huge amount of region shape information in a conventional region-based coding does not need to be transmitted in the new approach, because it can be synchronously obtained from a reconstructed picture in both the encoder and decoder by image segmentation. Segmented region updating, which can obtain appropriate regions for motion compensated prediction, and a new bit assignment algorithm in prediction error coding are also developed. Computer simulations are carried out to evaluate the coding efficiency at 9.6 kb/s. The result indicates that the objective and subjective qualities for decoded pictures are improved compared to those for the conventional block-based method. This algorithm is significantly effective for mobile communication.