Entropy-constrained Design of Quadtree Video Coding Schemes

The variable length code design of a complete quadtree-based video codec is addressed, in which we jointly optimize the entropy-coding for the parameters of motion-compensated prediction together with the residual coding. The quadtree coding scheme selected for this optimization allows easy access to the rate-distortion costs, thus making it possible to perform rate-distortion optimized bit allocation without exhaustive computation. Throughout the paper, we view the quadtree coder as a special case of treestructured entropy-constrained vector quantization and derive a design algorithm which iteratively descents to a (locally) optimal quadtree video codec. Experimental results evaluate the performance of the proposed design algorithm.