I want to do the embedding operation by converting Hessenberg

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I divided an image into 4x4 blocks and selected blocks randomly. Now I want to click on the selected Hessenberg matrix on these selected blocks and embed a binary image in the Hessenberg matrix. Thank you for your help.
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javad danesh
javad danesh 2022년 2월 13일
편집: javad danesh 2022년 2월 13일
Yes, I want to do that.

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Walter Roberson
Walter Roberson 2022년 2월 14일
Cover_filename = 'flamingos.jpg';
watermark_filename = 'cameraman.tif';
CoverImage = imresize(imread(Cover_filename), [256 256]);
watermarkImage = imresize( imread(watermark_filename), [8 8] );
watermarkBits = reshape((dec2bin(watermarkImage, 8) - '0').', 1, []);
num_watermarkBits = numel(watermarkBits);
image_blocks = mat2cell(CoverImage, 4 * ones(1,size(CoverImage,1)/4), 4 * ones(1,size(CoverImage,2)/4), ones(1,size(CoverImage,3)));
num_image_blocks = numel(image_blocks);
if num_image_blocks < num_watermarkBits
error('watermark image is too big to store in the cover image');
selected_blocks = randperm(numel(image_blocks), num_watermarkBits);
new_blocks = image_blocks;
displayed_once = false;
for idx = 1 : num_watermarkBits
blocknum = selected_blocks(idx);
thisblock = image_blocks{blocknum};
[P, H] = hess(double(thisblock));
H1 = typecast(H(1,end), 'uint64');
H1 = typecast(bitset(H1, 64, watermarkBits(idx)), 'double');
reconstructed_block = cast(P * H * P', class(thisblock));
new_blocks{blocknum} = reconstructed_block;
watermarkedImage = cell2mat(new_blocks);
figure(); imshow(CoverImage); title('Cover image');
figure(); imshow(watermarkImage); title('image to watermark with');
figure(); imshow(watermarkedImage); title('image after watermarking');
imshowpair(CoverImage, watermarkedImage)
Watermarked image is the same as the original image.
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javad danesh
javad danesh 2022년 2월 15일
No, I do not want you to read the article. Using the quantization method you mentioned, I want to place watermark bits in the overlay image in 4x4 block using the random function. But we also use this random function in the extraction so that the watermark is extracted correctly.
I used the following code.
for i=1:num_watermarkBits
[row col]=ind2sub([si_b(1),si_b(2)],s_r(i));
[P_R,H_R]=hess(double(b_r{row, col}));
if bw_R(i)==1
elseif bw_R(i)==0
b_r{row, col}=H_invR;
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javad danesh
javad danesh 2022년 2월 20일
I used the functions inside this folder.

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