一种改进的可变阈值SPIHT图像压缩算法

An Improved of SPIHT Algorithm Based on Variable Thresholds

针对传统小波变换过程复杂的缺点和SPIHT算法编码过程重复运算、存储量大的问题,首先分析了小波基和小波分解层数的选择,然后提出了一种新的可变阈值的SPIHT算法,该算法利用可变阈值对SPIHT算法中不重要像素列表(LIP)和不重要系数列表(LIS)进行分类得到一种更有效的编码算法。仿真结果表明,该算法的压缩整体性能要好于SPIHT算法。

In view of the problems of complicated convolution process of wavelet transform, repeated calculations and a large of needed memories of SPIHT algorithm. Firstly, the wavelet and decomposition of wavelet was analyzed by this paper. Secondly, it presents a more efficient implementation of the SPIHT algorithm by using variable thresholds to sort the list of insignificant pixels （LIP） and the list of the insignificant sets （LIS）. Finally, experimental results show that this algorithm is competitive to the SPIHT coding algorithm.