image steganography using LSB?

how can i segment image array every 3 bytes?

[DGM]

Define "segment array every three bytes". Are we to assume that the image is uint8? Is it a vectorized RGB image where each pixel is represented by three sequential bytes (assuming uint8)? ... or is it a proper MxNx3 array? If it's a MxNx3 array, which three bytes? columnwise? pagewise? What does any of this have to do with the title?

Maybe these will serve as examples:

% test RGB image
A = uint8(randi([0 50],10,10,3) + permute([0 100 200],[1 3 2]));
% rearrange pagewise into 3-element blocks
% each row is a color tuple representing one pixel
B = permute(reshape(A,[],1,3),[1 3 2])

% test RGB image (vectorized)
A = reshape(permute(A,[3 1 2]),[],1);
% rearrange into 3-element blocks
% each row is a color tuple representing one pixel
B = permute(reshape(A,3,[]),[2 1 3])

Answer 1

[yanqi liu]

yes，sir，may be use the byte to lsb image，such as

clc; clear all; close all;
% information
str = 'Hello, Abduellah Elbakoush';
txt_file = fullfile(pwd, 'demo.txt');
fid=fopen(txt_file,'wt');
fprintf(fid,'%s',str);
fclose(fid);
fid=fopen(txt_file,'r');
[msg, msg_num] = fread(fid,'ubit1');
fclose(fid);
% image
img=imread('cameraman.tif');
imo = img;
img=double(img);
[M, N] = size(img);
% LSB
k=1;
for c = 1:N
    for r = 1:M
        if k>msg_num
            break;
        end
        img(r,c) = img(r,c) - mod(img(r,c),2) + msg(k,1);
        k=k+1;
    end
end
% show
figure; imshow(uint8(img))