A VIDEO CODING ALGORITHM USING VECTOR-BASED TECHNIQUES

This paper presents an algorithm proposal submitted to MPEG-4 for vide o coding. The proposed algorithm addresses the functionality of improv ed coding efficiency for compression. It uses vector-based techniques for coding intraframes (the first frame and subsequent refreshing key frames) and motion-compensated difference frames. It uses the same mot ion estimation and motion compensation techniques as H.263. A video fr ame (I or P frame) is first decomposed into a set of vector bands usin g a vector wavelet transform. This stage of vector-based signal proces sing makes subsequent vector quantization in the vector bands very eff icient. Lattice vector quantization is then used in the vector bands. A 100% labeling efficiency is achieved for lattice vector quantization by using a set of generalized labeling algorithms for various importa nt lattices with pyramid and sphere boundaries. Finally, entropy codin g is used to code the indexes generated from lattice vector quantizati on. Our coding results have shown that a gain in peak signal-to-noise ratio (PSNR) up to 8 dB for intraframe coding and up to 6 dB for inter frame coding can be achieved over H.263. Subjective quality improvemen t of the proposed algorithm over H.263 can be easily observed.