wavelet based watermarking with dwt2 function in matlab it s an implementaton of an ieee paper.its a visible watermark it calculates the peak signal to noise ratio and the mean square error

利用多尺度小波分解函数dwt2对图像进行二尺度小波分解（仍然采用db1小波）-(Still using db1 wavelet multi-scale wavelet decomposition of the two-scale wavelet decomposition function dwt2 image)

单层小波变换对二维图像进行分解,[cA1,cH1,cV1,cD1]=dwt2(X, db1 ):计算图像X指定小波基的单层二维离散小波变换分解，其中cA为近似小波系数矩阵，参量cH,cV和cD分别为小波分解的水平细节系数、垂直细节系数和对角细节系数。-Single layer wavelet transform to the two-dimensional image decomposition, [cA1, cH1, cV1, cD1]=dwt2 (X, db1 ): X single ima