说明：  我们知道，图像压缩就是要寻找高压缩比、并使压缩后的图像有合适的信噪比的方法，对压缩后的图像还要能实现低失真度地恢复图像。压缩性能的评价标准之一是图像能量损失和零系数成分值。能量损失越小，零系数成分值越大，图像压缩的性能就越高。
(We know that image compression is to find a high compression ratio, and the compressed image signal to noise ratio suitable method for compressed images also can realize low-distortion image restoration. Compression performance evaluation criteria is one of image and zero energy loss coefficient of component values. The smaller the energy loss, the greater the value of a zero coefficient components, image compression the higher the performance.)