A FAST HIERARCHICAL MOTION-COMPENSATION SCHEME FOR VIDEO CODING USINGBLOCK FEATURE MATCHING

This paper presents a fast hierarchical feature matching-motion estima tion scheme (HEM-ME) that can be used in H.263, H.261, MPEG 1, MPEG 2, and HDTV applications, In the HFM-ME scheme, the sign truncated featu re (STP) is defined and used for block template matching, as opposed t o the pixel intensity values used in conventional block matching metho ds, The STF extraction process Can be considered as a zero-crossing ph ase detection with the mean as the bias and binary sign pattern as the phase deviation, Using the STF definition, a data block can be repres ented by a mean and a set of binary features with a much reduced data set, The block matching motion estimation is then divided to mean matc hing and binary phase matching, The proposed technique enables a signi ficant reduction in computational complexity compared with the convent ional full-search block matching ME because binary phase matching only involves Boolean logic operations, This feature also significantly re duces the data transfer time between the frame buffer and motion estim ator, The proposed HFM-ME algorithm is implemented and compared with t he conventional full-search block matching schemes, Our test results u sing three full-motion MPEG sequences indicate that the performance of the HFM-ME is comparable with the full-search block matching under th e same search ranges, however, HFM-ME can be implemented about 64 time s faster than the conventional full-search schemes, The proposed schem e can be combined with other fast algorithms to further reduce the com putational complexity, at the expense of picture quality.