Enhanced interframe coding based on morphological segmentation

Morphological segmentation has been proposed as an attractive alternative to transform-based compression for interframe coding of digital video. Being a spatial approach, segmentation based coding eliminates the artefacts commonly associated with transform coding, such as ringing around sharp edges. One disadvantage of this method is that it can introduce spurious edges in the reconstructed video sequence, associated with the boundaries of the transmitted regions. The authors present a statistically derived smoothing algorithm that reduces this problem. In addition, a single-stage entropy coder for the update signal is proposed in place of the conventional two-stage algorithm. Comparisons are made between the performance of a traditional motion compensated DCT coder and segmentation based codecs (with and without smoothing) for CIF sequences at bit rates between 64 and 256 kbps. It is concluded that, at the bit rates under investigation, the segmentation based method yields improved subjective quality of the reconstructed video.