Crop a 1m * 1m image along a 60 ° line, with a cutting area of 0.1m * 0.1m rectangle, for a total of 100 images

% 导入BMP图像
img = imread('your_image.bmp');
% 原始图像尺寸
original_height = size(img, 1); % 图像高度
original_width = size(img, 2); % 图像宽度
% 生成底角线上的点
x0 = linspace(0, original_width, 100); % 在底部生成100个点
y0 = linspace(0, original_height, 100); % 在左侧生成100个点
% 60°线方程 y = tan(60°) * x
tan_60_deg = tan(deg2rad(60)); % 将角度转换为弧度
y_line = tan_60_deg * x0;
% 裁剪图片
crop_size = [0.1*original_height, 0.1*original_width]; % 裁剪尺寸
for i = 1:100
    x_coord = round(x0(i)); % 取整数坐标
    y_coord = round(y_line(i));
    % 检查裁剪区域是否越界
    if x_coord + crop_size(2) > original_width || y_coord + crop_size(1) > original_height
        continue; % 越界则跳过
    end
    % 裁剪图片
    cropped_img = img(y_coord:y_coord+crop_size(1)-1, x_coord:x_coord+crop_size(2)-1, :);
    % 保存裁剪后的图片
    imwrite(cropped_img, sprintf('cropped_image_%d.bmp', i));
end

Starting from the bottom of the photo, draw a line where a point on the line is a vertex of the rectangular box, but I cannot achieve it

Thank you for your answers.

My email is [e-mail]

Answer 1

[VINAYAK LUHA]

Hi Brittney,

My understanding is that you want to draw a line with a 60-degree slope starting from the bottom left corner of your image. Further, you want to crop 100 rectangles, each measuring 0.1 times the image dimensions along this line, ensuring that the bottom left corner of each square aligns with the 60-degree line.

Assuming the size of the image to be 500px x 500px, refer to the following code snippet for achieving the above objective -

img = zeros(500, 500, 3);
img(:,:,3) = 1;

% Display the image
imshow(img);
hold on; % Hold the image to draw rectangles on it

% Original image dimensions
original_height = size(img, 1); % Image height
original_width = size(img, 2);  % Image width

% Generate points along the 60° line starting from the bottom-left corner
x0 = linspace(0, original_width, 100); % Generate 100 points along the x-axis

% Equation of the 60° line y = tan(60°) * x
tan_60_deg = tan(deg2rad(60)); % Convert angle to radians
y_line = tan_60_deg * x0;
plot(x0,original_height-y_line,color='g')

% Crop size (assuming 0.1 times the original dimensions)
crop_size = [0.1 * original_height, 0.1 * original_width]; % Square size

for i = 1:100
    x_coord = round(x0(i));
    y_coord = round(y_line(i));
    
    % Adjust y_coord to start from the bottom-left corner
    y_coord = original_height - y_coord;
    
    % Check if the square region is out of bounds
    if x_coord + crop_size(2) > original_width || y_coord - crop_size(1) < 1
        continue; % Skip if out of bounds
    end
    
    % Draw the rectangle
    rectangle('Position', [x_coord, y_coord - crop_size(1), crop_size(2), crop_size(1)], 'EdgeColor', 'r');
    
    %Crop rectangle and save
    cropped_img=imcrop(img, [x_coord, y_coord - crop_size(1), crop_size(2), crop_size(1)])
    imwrite(cropped_img, sprintf('cropped_image_%d.bmp', i));
end

hold off; % Release the hold on the image

Hope this helps,

Thanks

[Brittney]

thanks