Coding image sequence intensities along motion trajectories using EC-CELP quantization
N. Foodeei, Éric Dubois · 2002
The goal of this work is to investigate a high quality, low bit rate image sequence coding scheme which takes full advantage of the temporal redundancies. Such schemes will be important for high-compression video coding, such as the one studied in MPEG-4. In conventional image sequence coding, a motion-compensated DPCM configuration is used to remove the temporal redundancies. The performance of the DPCM for such highly correlated sources at rates below one bps degenerates substantially. We have recently shown that for a highly correlated Gauss-Markov source, practical near rate-distortion function performance is possible. We used the entropy-constrained code-excited linear predictive (EC-CELP) quantization scheme to obtain such performances. Hence for low rate image sequence coding, to improve the rate-distortion performance, an EC-CELP configuration can replace the DPCM configuration to quantize the image intensities along motion trajectories. To apply EC-CELP quantization, we first investigate the methods of motion trajectory estimation and propose a temporal block motion compensation configuration. Then, the performance advantage of EC-CELP configuration over the conventional DPCM structures is shown.>