关键词: 矢量量化, 码书, 旋转压缩

Abstract: A lot of correlations exist in original codebook by rotating each codeword to different directions，so a theory that an original codebook can be compressed by rotating codewords to different directions in Vector Quantization（VQ） algorithm is proposed.In this theory，all codewords in codebook are rotated to four hieratical directions to check their correlations.If correlations between two codewords with four directions exist，one codeword will be deleted from this codebook.So in compressed codebook，each codeword has four directions，it can be instead of four codewords.While encoding，the compressed codebook will be recovered by rotating codewords.An algorithm how to compress codebook by rotating codewords is also proposed and verified in this paper，a codebook can be compressed from 1 024×16×8 bit to 256×16×8 bit using this algorithm.Simulation results show that this codebook can decrease 75% memory room and I/O bandwidth but only lost 0.28 dB PSNR compared with the original codebook.

Key words: vector quantization, codebook, rotating compression