Optimizing block-coded motion parameters with block-partition graphs

We address the problem of optimizing block-coded motion parameters for use inside typical motion-compensating video encoders. We cast the given discrete problem as a nonsmooth nonconvex optimization problem which is defined over some graph, and solve it using the split primal-dual hybrid gradient algorithm. Although computational efficiency is not the main focus of this paper, an efficient, parallelized implementation of our proposed approach can be used as a way of performing rate-distortion optimal motion estimation in video encoders such as those following the H.264 or HEVC standard. Results from our experiments highlight the degree of sub-optimality demonstrated by motion parameters that have been computed by H.264 block matching algorithms.