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基于方向树结构矢量分类的小波图像网格编码矢量量化
Classified Vector Quantiztion of Wavelet Image Using Orientation Tree Structure Vector Combination
【摘要】 本文提出了采用方向树结构矢量组合并分类对小波图像进行网格编码矢量量化(TCVQ)的新方法。该方法矢量构成结合了子带系数的方向性,充分利用了子带系数带间和带内相关性,按能量和活跃度进行两级分类,降低了类中矢量的内部离散度,对活跃和非活跃类矢量实行加权TCVQ,利用卷积编码扩展信号空间,用维特比算法搜索最优量化序列,比使用加权 VQ提高了 0.7db左右。该方法编码计算复杂度适中,解码简单,有较好的压缩效果。
【Abstract】 A new method which performs trellis coded vector quantization(TCVQ) to wavelet image using orientation tree structure vector combination and classification is proposed. The’ method accords with the orientation of subbands coefficients to combine the vectors and exploits the correlation between the subbands and within the subbands fully. It makes two stages classification by the vector’s energy and activity and reduces the inner dispersion of the classified vectors. TCVQ is performed to active and inactive vectors.it uses convolution^ coding to expand signal space and uses Viterbi algorithm to find a optimized survived quantized sequence, it has an advantage of 0.7db or so over weighted VQ. The method has modest encoding complexity with simple decoding and can achieve much better compression effect.
【Key words】 Wavelet Transform Orientation Tree Structure Vector Vector Classification TCVQ;
- 【文献出处】 信号处理 ,Signal Processing , 编辑部邮箱 ,2002年01期
- 【分类号】TN919.8
- 【被引频次】3
- 【下载频次】62