Question

显示图3后，此代码出现问题。这两张图片没有添加。怎么纠正呢？该程序在封面图像文件名

中读取的封面图像的较低位平面中隐藏消息图像

%covername = input('Enter image file name with extension (like jennifer.bmp): ', 's'); 
%read in message image filename 
%messagename = input('Enter message image file name with extension: ', 's'); 
%open cover and message image files 
cover = imread('hand.jpg'); 
message = imread('coins.png'); 
%display on screen the two images 
figure(1), imshow(cover); title('Original Image (Cover Image)'); 
figure(2), imshow(message);title('Image to Hide (Message Image)'); 
%change to double to work with addition below 
cover=double(cover); 
message=double(message); 
%imbed = no. of bits of message image to embed in cover image 
imbed=4; 
%shift the message image over (8-imbed) bits to right 
messageshift=bitshift(message,-(8-imbed)); 
%show the message image with only embed bits on screen 
%must shift from LSBs to MSBs 
showmess=uint8(messageshift); 
showmess=bitshift(showmess,8-imbed); 
figure(3),imshow(showmess);title('4 Bit Image to Hide'); 
%now zero out imbed bits in cover image 
coverzero = cover; 
for i=1:imbed 
coverzero=bitset(coverzero,i,0); 
end 
cove=uint8(coverzero);
%now add message image and cover image 
stego = imadd(cove,messageshift); 
figure(4),imshow(stego);title('Stego image'); 
%save files if need to
%4 bit file that was embedded = same as file extracted 
imwrite(showmess,'showmess4.bmp');           
%use bmp to preserve lower bits
%jpg will get rid of them
%stego file imwrite(stego,'stego4.bmp');

Answer 1

我相信你的问题是imadd会给你错误“X和Y必须具有相同的大小和类或Y必须是标量双”。这暗示您的图像不相似。

如果你whos cove messageshift，你会发现cove是类uint8，而messageshift是double。只需将第16行中的messageshift转换为uint8，就像使用cove一样：

messageshift=uint8(bitshift(message,-(8-imbed)));

图像隐写术 - 隐藏图像中的图像

1 个答案: