Image Steganography [Matlab code]

Hiding Image in an Image using bit plane technique. This coding is for image steganography. Copy the code and execute in matlab.

%This program hides a message image in the lower

%bit planes of a cover image

%read in cover image filename

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(covername);

message = imread(messagename);

%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

%now add message image and cover image

stego = uint8(coverzero+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,'showmesscolor.bmp'); %use bmp to preserve lower bits

%jpg will get rid of them

%stego file

imwrite(stego,'stegocolor.bmp');