clear all;

Ximage=double(imread('C:\Documents and Settings\xdjsj\My Documents\zyh\program\Lena.jpg'));
Yimage=double(imread('C:\Documents and Settings\xdjsj\My Documents\zyh\program\Monkey.jpg'));
Zimage=double(imread('C:\Documents and Settings\xdjsj\My Documents\zyh\program\house.jpg'));
Ih=size(Ximage,1);%圖像的長度
Iw=size(Ximage,2);%圖像的寬度
Image=double(zeros(size(Ximage)));
Image=Zimage;
Dimage=Image;
s=1;
renewing=0;
hiding=0;
                            %                     隱                   藏
key1=4.0;
key2=0.1;

for(t=1:s)
figure(t)
subplot(2,2,1)
imshow(Ximage,[]);;%顯示圖像
title('待隱藏圖像1');

figure(t)
subplot(2,2,2)
imshow(Yimage,[]);
title('待隱藏圖像2');

figure(t)
subplot(2,2,3)
imshow(Image,[])
title('模板圖像');

for(i=1:Ih)
        for(j=1:2:Iw)
             Image(i,j)=(key2)*(Ximage(i,j)-Image(i,j))+Image(i,j);
             Image(i,j+1)=(key2)*(Yimage(i,j+1)-Image(i,j+1))+Image(i,j+1);
          
         end
end
figure(t)
subplot(2,2,4)
imshow(Image,[]);
title('結果圖像');
end


                 %                          恢                               復
key2=0.1;

for(t=1:s)
Ximage=double(zeros(size(Image)));
Yimage=double(zeros(size(Image)));
figure(t+s)
subplot(2,2,1)
imshow(Image,[]);
title('結果圖像');

figure(t+s)
subplot(2,2,2)
imshow(Zimage,[]);
title('模板圖像');
key=0; 

for(i=1:Ih)
       for(j=1:2:Iw-1)
                key=1/key2;
                Ximage(i,j)=mod(key*(Image(i,j)-Zimage(i,j))+Zimage(i,j),256);
                Image(i,j)=Ximage(i,j);
                
                Yimage(i,j+1)=mod(key*(Image(i,j+1)-Zimage(i,j+1))+Zimage(i,j+1),256);
                Image(i,j+1)=Yimage(i,j+1);
    
        end
      
end
for(i=1:Ih)
for(j=2:2:Iw-2)
    Ximage( i,j)=0.5*(Ximage( i,j-1)+Ximage(i,j+1));
    Yimage( i,j+1)=0.5*(Yimage( i,j)+Yimage( i,j+2));
end
end

figure(t+s)
subplot(2,2,3)
imshow(Yimage,[])
title('恢復圖像2');

figure(t+s)
subplot(2,2,4)
imshow(Ximage,[]);
title('恢復圖像1');

end


for(i=1:Ih)
        for(j=1:Iw)
            if(Image(i,j)~=Ximage(i,j))
                renewing=renewing+(Image(i,j)-Ximage(i,j))^2;
            end
        end
    end
    
   renewing=renewing/(Ih*Iw);
   renewing=renewing^(1/2);