Image Sequence Coding Using Vector Quantization

In this paper, a new interframe coding technique based upon vector quantization is presented. This algorithm has as its basis twodimensional block vector quantization, at the frame level, onto which is grafted the concept of adaptive codebook replenishment and frame replenishment. This algorithm includes three strategies: label replenishment, label replenishment with mean shift, and label replenishment with mean shift and selective codeword replacement. The last two strategies efficiently update the codebook to track the changes in local statistics on a frame basis. Compared with three-dimensional block vector quantization [16], for bit rates between 0.5 and 0.65 the normalized mean Squared error (NMSE) is reduced by a factor ranging between 2 and 2.5 by the use of replenishment.