校正任意形状DCT变换的矩阵不归一化，PSNR提高，基本是最佳校正方法-Calibration of arbitrary shape DCT transform matrix is not normalized, PSNR improve, the basic is the best correction method

This a matlab implementation for calculating PSNR-This is a matlab implementation for calculating PSNR

this file inciudes the signalto noise ratio of a steganographic scheme which is being used for embeding message in a jpeg image.