floor_round

clear;
% floor 
% Set rotation angle (in radians)
theta = 0.1 * pi / 2;

% Load image
colorimage = imread('test1.jpg');  

% Convert to double precision and split RGB channels
M = im2double(colorimage); 
MR = M(:,:,1); % Red
MG = M(:,:,2); % Green
MB = M(:,:,3); % Blue

% Get image size
rows = size(MR,1);  
cols = size(MR,2);  

% Define rotation matrix and its inverse
R = [cos(theta) -sin(theta); sin(theta) cos(theta)];
Rinv = R^(-1);

% Pad image to avoid cropping after rotation
padsize = 100;
MR_pad = padarray(MR, [padsize, padsize], 0, 'both');
MG_pad = padarray(MG, [padsize, padsize], 0, 'both');
MB_pad = padarray(MB, [padsize, padsize], 0, 'both');

[rows_pad, cols_pad] = size(MR_pad);
cx = cols_pad / 2;
cy = rows_pad / 2;

% Create new (blank) matrices for rotated image
MR_new = zeros(size(MR_pad));
MG_new = zeros(size(MG_pad));
MB_new = zeros(size(MB_pad));

% Basic rotation using hard rounding (push method)
for x = 1:cols_pad
    for y = 1:rows_pad
        % Shift origin to center
        x_shift = x - cx;
        y_shift = y - cy;

        % Apply rotation
        coord_new = R * [x_shift; y_shift];

        % Shift back
        x_new = floor(coord_new(1) + cx);
        y_new = floor(coord_new(2) + cy);

        % Check if new location is within bounds
        if x_new > 0 && x_new <= cols_pad && y_new > 0 && y_new <= rows_pad
            MR_new(y_new, x_new) = MR_pad(y, x);
            MG_new(y_new, x_new) = MG_pad(y, x);
            MB_new(y_new, x_new) = MB_pad(y, x);
        end
    end
end

% Combine the rotated channels back into an image
Mrotate(:,:,1) = MR_new;
Mrotate(:,:,2) = MG_new;
Mrotate(:,:,3) = MB_new;

% Display and save the rotated image
figure;
imshow(Mrotate);
title('Rotated Image (Hard Rounding)');
imwrite(Mrotate, 'RotatedImage.jpg');

%Show original vs rotated side by side
figure;
subplot(1,2,1), imshow(colorimage), title('Original');
subplot(1,2,2), imshow(Mrotate), title('Rotated');