Displacement Estimation By Hierarchical Blockmatching

A hierarchical blockmatching algorithm for the estimation of displacement vector fields in digital television sequences is presented. Known blockmatching techniques fail frequently as a result of using a fixed measurement window size. Using distinct sizes of measurement windows at different levels of a hierarchy, the presented blockmatching technique yields reliable and homogeneous displacement vector - fields, which are close to the true displacements, rather than only a match in the sense of a minimum mean absolute luminance difference. In the environment of a low bit rate hybrid coder for image sequences, the hierarchical blockmatching algorithm is well suited for both, motion compensating prediction, and motion compensating interpolation. Compared to other high sophisticated displacement estimation techniques, the computational effort is decreased drastically. Due to the regularity and the very small number of necessary operations, the presented hierarchical blockmatching algorithm can be implemented in hardware very easily.