i have written a code to hide a grayscale image within a rgb image.but while decrypting.the rgb image is retrieved.but the grayscale image is not.a black image is displayed instead.
3 views (last 30 days)
Show older comments
chaithra
on 28 Jan 2014
Commented: Soumyaa Ghosal
on 25 Apr 2017
%/encryption
p=imread('flower.jpg');
q=imread('msgimage.jpg');
p1=rgb2gray(p)
s=size(q);
[r c]=size(p1);
figure(1),imshow(q),title('original');
q2=imresize(q,[r c]);
qr=q2(:,:,1);
qg=q2(:,:,2);
qb=q2(:,:,3);
l=r*c;
qr=bitand(qr,uint8(240));
p2=bitshift(p1,-3);
im=bitor(qr,p2);
im=cat(3,qr,qg,qb);
%im1=imresize(im1,[s(1) s(2)]);
figure(2),imshow(p1);
figure(3),imshow(im),title('final');
=========================================
%/decryption
ir=im(:,:,1);
ig=im(:,:,2);
ib=im(:,:,3);
x=bitand(ir,uint8(240));
y=bitand(ir,uint8(15));
x=cat(3,ir,ig,ib);
figure(1),imshow(x);
figure(2),imshow(y);
0 Comments
Accepted Answer
Walter Roberson
on 28 Jan 2014
You have
im=bitor(qr,p2);
im=cat(3,qr,qg,qb);
which calculates im and then throws away that result and writes in a new one.
More Answers (1)
Shivaputra Narke
on 28 Jan 2014
Edited: Walter Roberson
on 28 Jan 2014
Use following code...
Compare code and find the changes done.
Hope this help..
%/encryption
p=imread('flowers.jpg');
q=imread('msgimage.jpg');
p1=rgb2gray(p)
s=size(q);
[r c]=size(p1);
figure(1),imshow(q),title('original');
q2=imresize(q,[r c]);
qr=q2(:,:,1);
qg=q2(:,:,2);
qb=q2(:,:,3);
l=r*c;
qr=bitand(qr,uint8(240));
p2=bitshift(p1,-3);
im=bitor(qr,p2);
im=cat(3,im,qg,qb);
%im1=imresize(im1,[s(1) s(2)]);
figure(2),imshow(p1);
figure(3),imshow(im),title('final');
%/decryption
ir=im(:,:,1);
ig=im(:,:,2);
ib=im(:,:,3);
x=bitand(ir,uint8(240));
y=bitand(ir,uint8(15));
x=cat(3,ir,ig,ib);
figure(1),imshow(x);
figure(2),imshow(y,[]);
2 Comments
Soumyaa Ghosal
on 25 Apr 2017
Can you please tell me which method of steganography is this ? Is this LSB or some other method ? Thanks in advance.
See Also
Categories
Find more on Matrix Indexing in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!