Video coding with a variable block-sizing technique in the wavelet transform domain

In this paper, we present an efficient video coding technique based on a variable block-sizing (VBS) technique and the wavelet transform. Quadtrees are used for VBS segmentation on the wavelet-transformed frame which is decomposed into pyramid multiresolution subbands. Feature areas are extracted during the growth of the quadtree on each subband. Motion estimation/compensation and vector quantization are performed on only the extracted feature areas in the subband. Since the VBS technique is very effective in lowering overall coding rates, the proposed coder is designed for very low bit-rate video coding. Simulation results are presented at 14.4 kbits/s for videoconferencing sequences. To evaluate the performance of the proposed coder, comparisons are made with results obtained by the H.263 standard (C) 1998 SPIE and IS&T. [S1017-9909(98)01003-4].