通过测量小波变换产生图像的熵、方差、最大值、最小值、平均值及各子图像内小波变换系数间的相关性来确定各子图像应采取的编码策略-Wavelet transform generated by measuring the image entropy, variance, maximum, minimum, average and sub-image with the wavelet transform coefficients of correlation between each sub-image