fixwatermark.m

实现小波数字水印

clc;
n=10;
h=imread('lena.jpg');
imshow(h)
h=double(h);
[CH LH]=wavedec2(h,3,'haar');
g=CH;
w=imread('ma.bmp');
imshow(w)
w=double(w);
w=w/256;
w=reshape(w,1,20*20);
for i=1:20*20
    if CH(i) >= 0
       CH(i)=n*(fix(CH(i)/n)+w(i));
    else
       CH(i)=n*(fix(CH(i)/n)-w(i));
    end
end
% for i=1:20*20
%     CH(i)=CH(i)+n*w(i);
% end
h=waverec2(CH,LH,'haar');
h=uint8(h);
figure
imshow(h)
h=double(h);
[CH LH]=wavedec2(h,3,'haar');
for i=1:20*20
    if CH(i) >= 0
        w(i)=CH(i)/n-fix(CH(i)/n);
    else
        w(i)=fix(CH(i)/n)-CH(i)/n;
    end
end
% for i=1:20*20
%     w(i)=(CH(i)-g(i))/n;
% end
w=reshape(w,20,20);
w=w*256;
w=uint8(w);
figure
imshow(w)