will someone find an error regard this code? because my watermaked modifed/inserted only left side of host image..

clc;

clear all;

hi=imread('Lena.tif');

[m,n]=size(hi);

area=m*n*8;

hi=dec2bin(hi); hi;

wi=imread('cameraman (2).tif');

b=imresize(wi,1/4);

imwrite(b,'wm.tif');

wi=imread('wm.tif');

[x,y]=size(wi);

wm=dec2bin(wi);

wlength=x*y*8;

i=1; j=1; k=1;

cnt=0;

while i<area

    cnt=cnt+1;

    if cnt>wlength;
        break;
    end

    hi(i,8)=wm(j,k);

    k=k+1;
    if k>8
        k=1;
        j=j+1;
    end
    i=i+1;
end

h1=bin2dec(hi);

[u,v]=size(h1);

h1=reshape(h1,m,n);

h1=uint8(h1);

wmm(1:m,1:n)=h1(1:m,1:n);

imshow(wmm);

imwrite(wmm,'w_image.tif');

imshow(wmm);

[Image Analyst]

Is lena.tif monochrome or color? Please attach your images so we can run your code on your exact images.

[SHALU SINGH]

sir, both images are gray and in tif format.lena's image size is 512*512 and cameraman's image size is 256*256. i am inserting small image because of limitation of lsb. the problem is here is my image is inserting at left side of the host image. i saw codes using bitget and bitset. but their recovered watermarked is lost one even without added noises. please help i want to tile a watermarked image. all over the host image. here i am attaching a file inserting a watermarked image at MSB of host image.

[Guillaume]

I created two dummy images like this:

lena = uint8(mod(repmat(0:511, 512, 1), 256)); %should be same size and type as your lena image
imwrite(lena, 'Lena.tif'); %create dummy lena image
cameraman = uint8(repmat((0:255)', 1, 256));
imwrite(cameraman, 'cameraman (2).tif');

and then ran your script.

It produced the expected result (cameraman image is properly embedded in lena image), so either you're not using the exact same code, or the images are not as you say.

[SHALU SINGH]

i used images and code same as i said... i thought the problem arises when i convert my image into a binary form.

[Guillaume]

Have you tried my example above (backup your images first, as it will overwrite them)? Does it not do what you want with the script you've posted?

Your code as written here is fine. It's not the most elegant but it does what you want. I wouldn't convert to binary strings and back and would rather use bitget and bitset but as I said, what you have works.

[SHALU SINGH]

there is an errors like, "Unsupported image datatype 'struct'." "error in imwrite validateSizes", "Unsupported image datatype 'struct'." i did't understand whats the problem here..

[Guillaume]

Sorry I made a typo the third line should have read:

cameraman = uint8(repmat((0:255)', 1, 256));

I've edited the comment to correct the error.