code.m

close all;
clear;

% Read Audio and Image 
[audio, fs] = audioread('around_the_world-atc.wav');
image = imread('lena.jpg');

% GrayScale Image Conversion 
grayimage = rgb2gray(image);
size_grayimage = size(grayimage);
conv_binary = uint8(zeros(size_grayimage(1), size_grayimage(2) * 8));

% Grayscale to Binary Conversion 
for i = 1:size_grayimage(1) 
    char_array = zeros(1, 8);
    for j = 1:size_grayimage(2)
        char_array = dec2bin(grayimage(i, j), 8);
        char_array = uint8(char_array);
        char_array = char_array - 48;
        for k = 1:8
            conv_binary(i, (j - 1) * 8 + k) = char_array(k);
        end
    end
end

conv_binary_single = reshape(conv_binary, [size_grayimage(1) * size_grayimage(2) * 8, 1]);
conv_binary_single = double(conv_binary_single);

% Divide Audio into Blocks
ElementsPerSegment = 128;
No_Of_Segments = ceil(length(audio) / ElementsPerSegment);
audiosegment = zeros(No_Of_Segments, ElementsPerSegment);

for i = 1:No_Of_Segments
    for j = 1:ElementsPerSegment
        if ((128 * (i - 1) + j) <= length(audio))
            audiosegment(i, j) = audio(128 * (i - 1) + j);
        end
    end
end

% Wavelet Decomposition and Modification
for i = 1:No_Of_Segments 
    [C(i, :), L(i, :)] = wavedec(audiosegment(i, :), 3, 'haar');
    [cd1(i, :), cd2(i, :), cd3(i, :)] = detcoef(C(i, :), L(i, :), [1 2 3]);
    [maximuma(i), indexa(i)] = max(cd3(i, :));
end

size_conv_binary_single = length(conv_binary_single); 
for i = 1:size_conv_binary_single
    if conv_binary_single(i, 1) == 0 
        alpha(i) = 0;
    else
        alpha(i) = double(sqrt(sum(cd3(i, :).^2) * 0.001) / conv_binary_single(i, 1));
    end  
end

for i = 1:size_conv_binary_single
    cd3(i, indexa(i)) = cd3(i, indexa(i)) + alpha(i) * conv_binary_single(i, 1);
end

for i = 1:size_conv_binary_single
    C(i, 32 + indexa(i)) = cd3(i, indexa(i));
end

for i = 1:size_conv_binary_single 
    audiomodifiedsegment(i, :) = waverec(C(i, :), L(i, :), 'haar');
end

% Combine all modified segments into a single audio signal
finalaudio = zeros(size(audio));  % initialize to original audio size
for i = 1:size_conv_binary_single
    start_idx = (i - 1) * ElementsPerSegment + 1;
    end_idx = start_idx + ElementsPerSegment - 1;
    finalaudio(start_idx:end_idx) = audiomodifiedsegment(i, :);
end

% Save the final modified audio
audiowrite('DWT_OUTPUT_image.wav', finalaudio, fs);

% Plot the Full Original Audio Signal
figure;
plot(audio);
title('Full Original Audio Waveform');
xlabel('Sample');
ylabel('Amplitude');

% Plot the Full Modified Audio Signal
figure;
plot(finalaudio);
title('Full Modified Audio Waveform');
xlabel('Sample');
ylabel('Amplitude');

% Plot Zoomed-in View of Original Audio Signal for Detail
figure;
plot(audio);
title('Zoomed-in Original Audio Waveform');
xlabel('Sample');
ylabel('Amplitude');
xlim([1 2000]); % adjust for a specific portion

% Plot Zoomed-in View of Modified Audio Signal for Detail
figure;
plot(finalaudio);
title('Zoomed-in Modified Audio Waveform');
xlabel('Sample');
ylabel('Amplitude');
xlim([1 2000]); % adjust for a specific portion

% Display the Grayscale Image
figure;
imshow(grayimage);
title('Grayscale Image of Lena');

% Plot the Histogram of the Grayscale Image
figure;
histogram(grayimage(:), 256);
title('Histogram of Grayscale Image');
xlabel('Pixel Intensity');
ylabel('Frequency');