一种基于SPIHT算法的小波图像编码

在研究图像小波分解系数特点与SPIHT算法的基础上，针对SPIHT算法中三张链表在编码过程中以同一模式处理仍存在冗余，提出了一种基于SPIHT算法的小波图像编码。算法采用分区间处理，对LIP、LIS、LSP三张链表在不同的系数范围内采取不同的编码模式，当阈值减少时四邻域中同一量化级的重要系数个数明显增加，并且绝对数值较接近，编码时只保存这几个重要系数的平均值。给出了实验结果，并与原SPIHT算法比较，结果表明：文章给出的编码方法的编码性能优于原算法。

A Kind of Wavelet Image Coding Based on SPIHT Algorithm

After the studying of image wavelet decomposing coefficients and SPIHT algorithm, wavelet image coding algorithm is introduced based on SPIHT, which aims at solving the redundance problem existing in three link tables coding The algorithm adopt different coding mode according t table LIP, LIS and LSP. When threshold value decre with close same quantization level increase greatly in four to each other, so only the averages of these sig of SPIHT even processed by same mode. o different coefficients range in three link ase. the number of significant coefficients domain,the absolute nificant coefficients are values of coefficients are saved in coding The experiment results of the algorithm are compared with SPIHT algorithm, and show algorithm is excelled in PSNR and bpp. process. that the