读入一幅256*256图像，将它分成8*8pixel的若干块，对每块做DCT变换，保留Z型顺序的若干变换系数，进行IDCT重构图像，计算重构图像的信噪比-Reading a 256* 256 image, it will be divided into several blocks of 8*8 pixel, keep each optimal Z transformation of sequence number, IDCT transform coefficient calculation

DCT and Image Compression In the JPEG image compression algorithm, the input image is divided into 8-by-8 or 16-by-16 blocks, and the two-dimensional DCT is computed for each block. The DCT coefficients are then quantized, coded, and trans