对图像进行二维离散小波变换, 变换级数大于等于3级,然后统计系数中0的个数（百分比表示），并进行重构, 最后计算重构图像的峰值信噪比(PSNR). 里面还附上了我写的实验报告，对大家理解Mallat算法和图像压缩很有帮助-Image two-dimensional discrete wavelet transform, transform series greater than or equal to 3, and then statistics of the number of c