一种改进的基于Hadamard变换的快速码字搜索算法

An Improved Codeword Search Algorithm Based on Hadamard Transform

提出了一种矢量量化码字搜索的快速算法。该算法是在Hadamard变换域内进行的。匹配码字的判决过程首先根据Chebyshev误差测度,在码书中找出一定数量Chebyshev误差最小的码字;然后运用部分失真搜索算法(PDS),在上述码字中找出其中最匹配的码字。从理论分析和模拟实验结果表明,该算法在保证较好的性能指标和视觉效果前提下,明显减少码字搜索时间。

A fast algorithm of VQ codeword search is proposed. This algorithm performs a fast codeword search in the Hadamard transform（HT） domain. The process to get the best matched codeword is as follows： First, sonie number codewords in which Chebyshev distortion is the minimum are selected from the codebook according to the Chebyshev distortion measure. Second, the best matched codeword can be gained from above codcwords based on the partial distortion search （PDS） algorithm. The simulation and theory analysis show that the codeword searching time in the algorithm has been reduced greatly on precondition of good performance and visual effect.