Object-based video coding by global-to-local motion segmentation

We describe an object-based video compression scheme based on the derivation and efficient coding of motion boundaries. First, we recursively identify a small number of global movement classes, each represented by two or more motion parameters. Second, we assign regions of a spatial segmentation to movement classes. Third, we merge segments using various similarity heuristics, while adding movement classes for small objects, if necessary. Finally, the boundaries of motion are coded using an efficient asymmetric binary tree coding scheme. Experimental results on standard test sequences qualitatively show that the proposed algorithm gives good segmentation, and that it is suitable for very-low-data-rate object-based coding.