Video subband VQ coding at 64 kbit/s using short-kernel filter banks with an improved motion estimation technique

摘要

A motion compensated interframe prediction (MCIP) coder incorporating short-kernel subband filter-banks with an improved motion estimation technique is described. The coder is based on two-dimensional subband decomposition of the error image obtained after motion compensated interframe prediction. The luminance and chrominance subbands, generated after the decomposition process, form image vectors which are then quantized using vector quantization. The block matching method works well with low velocities and low noise content in the image frames. For a motion compensation estimation algorithm to cope with higher activity image frames, it is important that rapid movements, having high-amplitude motion vectors, are effectively recognized. It is also essential that the motion estimation performance does not degrade due to noise in the previously decoded frame. To achieve this, a combination of phase correlation and block search methods is applied sequentially to a hierarchy of low-pass filtered and subsampled images, while the motion vectors are progressively refined at each step of the process. Details of the proposed coding algorithm and simulation results operating at 64 kbits/s are presented.