Finite state vector quantization with multipath tree search strategy for image/video coding

Abstract

This paper presents a new vector quantization (VQ) algorithm exploiting the features of tree-search as well as finite state VQs for image/video coding. In the tree-search VQ, multiple candidates are identified for on-going search to optimally determine an index of the minimum distortion. In addition, the desired codebook has been reorganized hierarchically to meet the concept of multi-path search of neighboring trees so that picture quality can be improved by 4 dB on the average. In the finite state VQ, adaptation to the state codebooks is added to enhance the hit-ratio of the index produced by the tree-search VQ and hence to further reduce compressed bits. An identifier code is then included to indicate to which output indices belong. Our proposed algorithm not only reaches a higher compression ratio but also achieves better quality compared to conventional Anite-state and tree-search VQs.