% Experiment 1: Introduction to MATLAB and Image Processing
% (MATLAB Onramp and Image Processing Onramp)
clear; close all; clc;

%% Part A: MATLAB basics (MATLAB Onramp)
x = 0:0.05:2*pi;                 % row vector using the colon operator
y = sin(x);                      % element-wise function evaluation
A = magic(4);                    % 4 x 4 matrix
B = A';                          % transpose
C = A .* B;                      % element-wise multiplication
fprintf('Size of A          : %d x %d\n', size(A, 1), size(A, 2));
fprintf('Sum of column 1 of A: %d\n', sum(A(:, 1)));
fprintf('Max element of A.*B : %d\n', max(C(:)));
fprintf('Mean of sin(x)      : %.4f\n', mean(y));

figure('Name', 'A_matlab_basics');
plot(x, y, 'b-', 'LineWidth', 1.5); hold on;
plot(x, cos(x), 'r--', 'LineWidth', 1.5); hold off;
grid on; legend('sin(x)', 'cos(x)');
xlabel('x (radians)'); ylabel('Amplitude');
title('Plotting vectors in MATLAB');

%% Part B: Image Processing basics (Image Processing Onramp)
rgbImg = imread('peppers.png');
imgInfo = imfinfo('peppers.png');
fprintf('Image size  : %d x %d x %d\n', size(rgbImg, 1), size(rgbImg, 2), size(rgbImg, 3));
fprintf('Image class : %s, bit depth %d\n', class(rgbImg), imgInfo.BitDepth);

grayImg = rgb2gray(rgbImg);          % colour to grayscale
adjImg  = imadjust(grayImg);         % contrast adjustment
bwImg   = imbinarize(grayImg);       % thresholding (Otsu)
fprintf('Gray range  : [%d %d], after imadjust: [%d %d]\n', ...
    min(grayImg(:)), max(grayImg(:)), min(adjImg(:)), max(adjImg(:)));
fprintf('Foreground pixels in binary image: %.2f %%\n', 100 * mean(bwImg(:)));

figure('Name', 'B_image_basics');
subplot(2, 3, 1); imshow(rgbImg);  title('RGB image');
subplot(2, 3, 2); imshow(grayImg); title('Grayscale (rgb2gray)');
subplot(2, 3, 3); imshow(adjImg);  title('Adjusted (imadjust)');
subplot(2, 3, 4); imhist(grayImg); title('Histogram of gray image');
subplot(2, 3, 5); imhist(adjImg);  title('Histogram after imadjust');
subplot(2, 3, 6); imshow(bwImg);   title('Binary (imbinarize)');