Motion compensated transform coding of video using hierarchical displacement field and global rate-distortion optimization

Seeking a more efficient video coding scheme for low-bit-rate video communication, we enhance the conventional motion-compensated discrete-cosine-transform coding scheme by using (i) a nonuniformly sampled displacement field, constructed from a multiresolution hierarchy of component displacement fields, and (ii) “global” optimization of bit allocation, jointly between the displacement field hierarchy and the motion compensated prediction residual. Our simulation results demonstrate that, for bit rates in the 10-64 kb/s range and for various common test sequences, the enhanced scheme outperforms the conventional scheme by between 1-3 dB of PSNR. The enhanced scheme performs well because it is allowed to judiciously exploit temporal redundancy to a much greater extent than the conventional scheme