錯誤恢復文本隱藏到圖像

Question

我正在隱藏文本到圖像..但我無法得到確切的文本消息回..可以有人plz幫助我在整理的問題和錯誤我的代碼.. K I正在使用的值是2。這裏的代碼如下：

clc; 
close all; clear all; 
clf; 
cov_img=imread('pears.png'); 




cov_img1 =rgb2gray(cov_img); 
cov_img1=imresize(cov_img1,[256 256]); 
imshow(cov_img1); 

k=input('enter no of bits '); 
a='In this context, cryptography, steganography and water marking schemes play a vital role in establishing secret communication through encryption, hiding and embedding secret information in digital medium respectively. '; 

b=dec2bin(double(a),8); 
c=b(:); 


d=reshape(c,[],k); 


e=bin2dec(d); 
[m n]=size(e); 


for i=1:256; 
    for j=1:256; 

    S(i,j)=cov_img1(i,j)-mod(cov_img1(i,j),2^k)+e(i,:); 

    j=j+1; 
    end 
    i=i+1; 
end 

figure, imshow(S,[]); 


%%Extraction 

for i=1:256; 
    for j=1:256; 
     E(i,j)=mod(double(S(i,j)),2^k); 
     j=j+1; 
    end 
    i=i+1; 
end 


e1=dec2bin(E,2); 

e2=e1'; 

e3=reshape(e1,[],8); 

e4=bin2dec(e3); 

e5=char(e4); 

disp(e5) 

[mse psnr]=msepsnr(cov_img1,S); 
disp('PSNR value is : '); 
disp(psnr); 
disp(' db'); 
disp('MSE value is'); 
disp(mse); 
%%%%%%% 

Answer 1

我不完全理解的方法，但你不會得到完整的消息早在e是長度872，而我只運行到256.因此S不會包含您的完整信息。你也不需要在Matlab的for循環中做j = j + 1。以下作品適用於我（即使e的長度在e1的定義中可能未知）：

clc; 
close all; clear all; 
clf; 
cov_img=imread('pears.png'); 

cov_img1 =rgb2gray(cov_img); 
cov_img1=imresize(cov_img1,[256 256]); 
imshow(cov_img1); 

k=2; 
a='In this context, cryptography, steganography and water marking schemes play a vital role in establishing secret communication through encryption, hiding and embedding secret information in digital medium respectively. '; 
b=dec2bin(double(a),8); 
c=b(:); 
d=reshape(c,[],k); 
e=bin2dec(d); 
[m n]=size(e); 

Z = zeros(256); 
Z(1:length(e)) = e; 
for i=1:256; 
    for j=1:256; 

    S(i,j)=cov_img1(i,j)-mod(cov_img1(i,j),2^k)+Z(i,j); 

    end 

end 
figure, imshow(S,[]); 
%%Extraction 
for i=1:256; 
    for j=1:256; 
     E(i,j)=mod(double(S(i,j)),2^k)'; 

    end 

end 
e1=dec2bin(E(1:length(e)),2); 
e2=e1; 
e3=reshape(e2,[],8); 
e4=bin2dec(e3); 
e5=char(e4); 
disp(e5')