Embed watermark in background of an document image

I need code to embed and extract watermark in background of a document image.

[Walter Roberson]

https://bytescout.com/products/developer/watermarkingsdk/watermarkingsdk_first_step_with_c_charp.html

[Balkar Singh]

Thank you sir g.But I need the code in matlab.

[Image Analyst]

Hidden or visible?

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Balkar Singh]

Visible

[Walter Roberson]

https://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Image Analyst]

https://www.mathworks.com/products/computer-vision.html#feature-detection

[Walter Roberson]

Good point -- in order to add a watermark in the background, you have to be able to figure out which parts of the image are the background.

Unfortunately, there is no reliable way of figuring that out. For example, if you are given a picture of the Sun, then if you are studying the Sun then the main portion is the foreground and everything else is background, but if you are studying solar comments making close approaches to the Sun, then you want to block the Sun out as background, and the other little blobs in the image become the foreground. No program, given just the image, can know from the image alone what part of the image is foreground or background, because foreground and background have to do with intent rather than with inherent properties of the image.

[Balkar Singh]

Respected Sir, any solution regarding my problem.

[KALYAN ACHARJYA]

@Balkar Singh Have you followed the reffered links?

[Balkar Singh]

@KALYAN ACHARJYA yes sir, but did not get solution related to my problem.

[Walter Roberson]

Which algorithm did you decide upon? What error did you encounter in your MATLAB implementation of the algorithm?

[Balkar Singh]

clear all;

a1=imread('Marksheet1.png');

a2=imresize(a1, [256 256]);

a = a2(1:256,1:256,1);

blk1 = our_blkproc(a,blksize1);

cover_img = zeros(8,8,size(blk1,3));

for i=1:size(blk1,3)

cover_img(:,:,i) = dct2(blk1(:,:,i));

end

% cover_img1 = cover_img/2;

b1 = imread('logo.png');

b2 = imresize(b1, [128 128]);

blksize2=[8,8];

b = b2(1:128,1:128,1);

blk2 = our_blkproc(b,blksize2);

water_img = zeros(8,8,size(blk2,3));

for i=1:size(blk2,3)

water_img(:,:,i) = dct2(blk2(:,:,i));

end

%water_img = water_img/2;

%final_value = zeros(8,8,size(blk1,3));

final_value = cover_img;

cnt1=0;

for i = 1:size(water_img,3)

final_value(1,1,i) = water_img(1,1,i);

cnt1=cnt1+1;

end

dct_inv = zeros(8,8,size(final_value,3));

cnt2=0;

for i=1:size(final_value,3)

dct_inv(:,:,i) = idct2(final_value(:,:,i));

cnt2=cnt2+1;

end

output = our_blkproc_rev(dct_inv);

imshow(uint8(output))

Sir, I tried this code