On the fast search algorithms for vector quantization encoding

One of the major difficulties arising in vector quantization (VQ) is high encoding time complexity. Based on the well-known partial distance search (PDS) method and a special order of codewords in VQ codebook, two simple and efficient methods are introduced in fast full search vector quantization to reduce encoding time complexity. The exploitation of the "move-to-front" method, which may get a smaller distortion as early as possible, combined with the PDS algorithm, is shown to improve the encoding efficiency of the PDS method. Because of the feature of energy compaction in DCT domain, search in DCT domain codebook may be further speeded up. The experimental results show that our fast algorithms may significantly reduce search time of VQ encoding. (C) 2003 Wiley Periodicals, Inc.