The authors have developed a method to reduce the code search efforts in Vector Quantization by using continuity of physical signals and their geometiric relation, while keeping the minimal distortion condition. Suppose a codebook designed by the LBG algorithm is given. The algorithm proposed here is based on an assumption that there is some, hopefully good, estimate of the current code, for example, the previous code in the case of speech signal- The distance between the input vector and the previous code becomes a upper bound of the distortion. Distances among code vectors are tabulated in the increasing order for each of them, and used in order to decrease the number of code vectors examined in the quantization phase. The experimental results on speech and picture data proved that the calculation efforts were reduced by several times without increase of distortions comparing with the original full search algorithm.
Bibliographic reference. Kobayashi, Yutaka / Niimi, Yasuhisa (1989): "An efficient VQ code search algorithm using signal continuity", In EUROSPEECH-1989, 1446-1449.