图像隐写术-将图像隐藏在图像中答案

【问题标题】：image steganography- hiding an image within an image图像隐写术-将图像隐藏在图像中
【发布时间】：2014-02-18 04:25:07
【问题描述】：

显示图3后这段代码有问题。这两个图像没有被添加。如何纠正它？该程序在封面图像文件名中读取的封面图像的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');

【问题讨论】：

标签： matlab steganography

【解决方案1】：

我相信您的问题是 imadd 给您错误“X 和 Y 必须具有相同的大小和类或 Y 必须是标量双精度数”。这表明您的图像不相似。

如果您执行whos cove messageshift，您将看到 cove 是 uint8 类，而 messageshift 是双倍。只需在第 16 行将 messageshift 转换为 uint8，就像您对 cove 所做的那样：

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

【讨论】：