To overcome unstable performance and improve the quality of random initial codebook for LBG algorithm based on spatial domain, a novel algorithm based on wavelet domain is proposed. It constructs vectors by parent-child relationship between wavelet coefficients, and uses separated method to choose the initial codebook. It considers the relationships in and between subbands. Two pictures are used to simulate the algorithm. Simulation results show that it has faster convergence speed, higher compression rate and higher compression quality than random LSB and random LSB based on wavelet transform.%针对LBG算法在图像空域中随机构造初始码书性能不稳定、压缩质量差的缺点,提出了一种新的基于小波变换的变换域初始码书构造方法.该算法利用小波分解后系数的父子关系构造训练矢量,在此基础上采用分离的初始码书算法,考虑了子带内部以及各子带之间的关联性.用两幅经典图像做了算法的性能仿真与比较.仿真结果表明,该算法与传统的随机LBG以及一般的小波随机LBG算法相比,具有收敛速度快、压缩比高、图像质量好的优点.
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