主辅扫描混合编码的嵌入零树小波改进算法

Improved EZW Algorithm of Dominant and Subordinate Pass Mix-coding

提出了主辅扫描混合编码的嵌入式零树小波(EZW)改进算法。使前一阈值下大系数的辅扫描编码和解码优先进行,构成一个新的辅扫描过程;合并了主扫描和新发现的大系数的辅扫描为一个新的主扫描过程,使编码和解码更精细有效。实验结果表明,与传统的EZW算法相比,该改进算法明显提高了图像压缩的峰值信噪比。

Improved embedded zero-tree wavelet （EZW for short） algorithm of dominant and subordinate pass mix-coding is presented. The subordinate pass of big coefficients that belong to a previous threshold becomes the first step during the encoding process. The dominant pass and the subordinate pass that constituted by the new big coefficients are combined to a new dominant pass, It makes encoding and decoding effective. Experimental result shows that compared to the traditional EZW, the improved algorithm can increase the peak Signal to noise radio （ PSNR for short） of image compression.