Optimal Pruning Quad-Tree Block-Based Binary Shape Coding

In object-based video coding, shape masks are used to specify the shape of a video object. The binary shape means each pixel is either background or object. In this paper, we present a new lossless block-based coding algorithm for binary shapes that combines a quad-tree structure with block-based arithmetic coding; an optimal pruning quadtree structure searching algorithm is proposed to further reduce the spatial redundancy of quad-tree blocks. Experimental results demonstrate that this new approach provides a saving in bits generated between approximately 40-75% compared to the MPEG-4 binary shape coding algorithm