Research On Vector Quantization Codebook Design And Application

With the rapid development of information, communication and other regions, there have been more and more multimedia information, such as speech, image and so on, needed to been stored, processed and transmitted. Due to the large amount of multimedia information, we need huge storage space and broad channel bandwidth. In order to improve storage efficiency and reduce storage space, the redundancy of multimedia information should been eliminated as much as possible while the introducing distortion is allowable. Vector quantization (VQ) is an efficient lossy compression technique, whose prominent virtues are high compression ratio and simple decoding process, so it has become one of important compression techniques for speech and image coding. VQ technique is not only useful for information compression, but speaker identification, digital watermarking, speech recognition, image recognition, literature retrieval and so on. So, VQ technique is of great researching value.As to VQ, there are three key techniques, i.e., codebook design, codeword search and codeword index assignment, and codebook design is the most important comparing with the two other techniques. Codebook design is mostly to obtain an optimal classification for the training vectors, that means getting the optimal scheme for dividing the M k-dimension training vectors to N classifications. An efficient codebook is critical for compression coding, VQ-based speaker recognition and VQ-based digital watermarking. This dissertation stresses analyzing the classic algorithms of codebook design, meanwhile investigates the improved scheme and optimization algorithm for codebook design. On the base of these researches mentioned above, combining with relevant theory and technique of speech signal process and image process, novel VQ-based speaker recognition strategy and VQ-based digital watermarking technique are put in focus.To sum up, the main work and feature of this paper are as follows:1. The classic codebook design algorithm LBG has been used in broad application, but this algorithm usually gets a local optimal codebook. It has been an important researching orientation to optimize codebook by revolutionary algorithms in the...