Steganography in Digital Image Processing & its implementation in MATLAB || LSB based ||Watermarking

Video lecture series on Digital Image Processing, Lecture: 79, Steganography in Digital Image Processing & its implementation in MATLAB || LSB based ||Watermarking Implementation of grayscale and color image steganography in MATLAB Link to download ppts/lecture notes: https://drive.google.com/drive/folders/1AtR1eq6ZvQf-5vjXEMUPXNj2S0d9rAMZ?usp=share_link #DIP #DIPwithMATLAB #DigitalImageProcessingUsingMATLAB #digitalimageprocessing #digitalimageprocessinglecturesin4K #studywithdrdafda The MATLAB codes used in the video is given below: % Steganography grayscale image clc close all clear all original = imread('cameraman.tif'); original = double(original); [row col] = size(original); secret = imread('testpat1.png'); secret = double(secret); for x = 1:1:row for y = 1:1:col temp1 = dec2bin(original(x,y),8); temp2 = dec2bin(secret(x,y),8); temp1(8) = temp2(1); % Replacing the LSB with the MSB temp1(7) = temp2(2); % If we replace more than 1 bit temp1(6) = temp2(3); % we start getting the watermark temp1(5) = temp2(4); %temp1(4) = temp2(5); stego(x,y) = bin2dec(temp1); end end stego = uint8(stego); imwrite(stego,'C:\Users\alpes\Documents\MATLAB\newimage.tif'); % above line will create image in our existing folder subplot(2,2,1) imshow(uint8(original)) title('Carrier Image'); subplot(2,2,2) imshow(uint8(secret)) title('Secret Image'); subplot(2,2,3) imshow(uint8(stego)) title('Stego Image'); %%% Retrieval of Secret Data image = imread('C:\Users\alpes\Documents\MATLAB\newimage.tif'); image = double(image); [row col] = size(image); for x = 1:1:row for y = 1:1:col temp = dec2bin(image(x,y),8);% This gives a character value if (temp(8)=='0') temp='00000000'; secret_data(x,y)=bin2dec(temp); else temp='11111111' secret_data(x,y) = bin2dec(temp); end end end subplot(2,2,4) imshow(secret_data) title('Retrieved Image'); % Steganography color image clc; clear; close all; % Step 1: Read the Carrier (Cover) Image and Secret Image a = imread('Maulik.png'); subplot(2,2,1); imshow(a); title('Carrier Image'); x = imread('DD.png'); subplot(2,2,2); imshow(x); title('Secret Image'); % Step 2: Resize the Secret Image to Match the Carrier Image [r, c, ~] = size(a); x = imresize(x, [r, c]); % Step 3: Extract RGB Channels from the Images ra = a(:,:,1); ga = a(:,:,2); ba = a(:,:,3); rx = x(:,:,1); gx = x(:,:,2); bx = x(:,:,3); % Step 4: Embed Secret Image into the Carrier Image (LSB Embedding) embedLSB = @(carrier, secret) bitand(carrier, 254) + bitand(secret, 128)/128; redsteg = zeros(r, c); for i = 1:r for j = 1:c redsteg(i,j) = embedLSB(ra(i,j), rx(i,j)); end end greensteg = zeros(r, c); for i = 1:r for j = 1:c greensteg(i,j) = embedLSB(ga(i,j), gx(i,j)); end end bluesteg = zeros(r, c); for i = 1:r for j = 1:c bluesteg(i,j) = embedLSB(ba(i,j), bx(i,j)); end end % Step 5: Combine the Modified Channels to Create the Stego Image finalsteg = cat(3, redsteg, greensteg, bluesteg); finalsteg = finalsteg ./ max(finalsteg(:)); % Normalize to 0-1 range subplot(2,2,3); imshow(finalsteg); title('Stegmented Image'); % Step 6: Extract Secret Image from the Stego Image (LSB Extraction) extractLSB = @(stego) bitand(stego, 1) * 128; recoveredr = zeros(r, c); for i = 1:r for j = 1:c recoveredr(i,j) = extractLSB(redsteg(i,j)); end end recoveredg = zeros(r, c); for i = 1:r for j = 1:c recoveredg(i,j) = extractLSB(greensteg(i,j)); end end recoveredb = zeros(r, c); for i = 1:r for j = 1:c recoveredb(i,j) = extractLSB(bluesteg(i,j)); end end % Step 7: Combine the Recovered Channels to Reconstruct the Secret Image output = cat(3, recoveredr, recoveredg, recoveredb); subplot(2,2,4); imshow(output); title('Recovered Image');