www.gusucode.com > ​数字水印算法实现（matlab程序包），包含有DCT水印嵌入算法源码程序 > watermark综述+代码/test2.m

    A = double(imread('lena.bmp'));
figure(1);
imshow(uint8(A));
imgsize = size(A,1)*size(A,2);
seed = 123;
rand('state',seed);
pn=rand(size(A,1),size(A,2));
AW = A + pn ;
figure(2);
imshow(uint8(AW));
figure(3);
imshow(uint8(pn));
cor1 = sum(sum(pn.*A))