Morphological motion field representation for region-based image sequence coding
We introduce a novel region-based video compression framework that uses a morphological operation to efficiently capture motion correspondences between consecutive frames in an image sequence. Our coder is built on the observation that the motion field associated with typical image sequences can be segmented into component motion subfield "clusters" associated with distinct objects or regions in the scene, and further that these clusters can be efficiently captured using morphological operators in a "backward" framework that avoids needing to explicitly send object boundaries. Cluster matching is used in lieu of the conventional block matching methods of standard video codecs to define a cluster motion representation paradigm. Experimental coding results show about 10-20% reduction in prediction error energy and 0.3-1 db (average of about 0.44 dB) reduction in the final residue-coded peak signal to noise ratio (PSNR) using our proposed motion compensation framework on the football sequence over standard block motion compensation methods like MPEG, while also requiring less computational complexity.