# Image Processing Dimension Error

1 回表示 (過去 30 日間)
Zahryn Martinez 2023 年 7 月 10 日
コメント済み: Zahryn Martinez 2023 年 7 月 10 日
Here is the Question I am working on. Below is also the matlab code I have written, but towards the end I get an error talking about how the "index in position 2 exceeds array bounds". Any ideas?
%* Part A *%
% Translation vector
translation = [10; -25; 40];
% Euler angles representing the orientation (REPLACE THESE ANGLES)
theta_x = -1; % Angle around X-axis in radians
theta_y = 0.7; % Angle around Y-axis in radians
theta_z = -0.5; % Angle around Z-axis in radians
% Compute the rotation matrices
Rx = [1, 0, 0; 0, cos(theta_x), -sin(theta_x); 0, sin(theta_x), cos(theta_x)];
Ry = [cos(theta_y), 0, sin(theta_y); 0, 1, 0; -sin(theta_y), 0, cos(theta_y)];
Rz = [cos(theta_z), -sin(theta_z), 0; sin(theta_z), cos(theta_z), 0; 0, 0, 1];
% Combine the translation and rotation matrices
cW_H = [Rx * Ry * Rz, translation; 0, 0, 0, 1];
% Display the transformation matrix
disp("Part A")
Part A
cW_H
cW_H = 4×4
0.6712 0.3667 0.6442 10.0000 -0.7348 0.2143 0.6436 -25.0000 0.0980 -0.9053 0.4132 40.0000 0 0 0 1.0000
%* Part B *%
% Compute the inverse transformation matrix
wC_H = inv(cW_H);
% Display the inverse transformation matrix
disp("Part B")
Part B
wC_H
wC_H = 4×4
0.6712 -0.7348 0.0980 -28.9996 0.3667 0.2143 -0.9053 37.9032 0.6442 0.6436 0.4132 -6.8822 0 0 0 1.0000
%* Part C *%
% Image size
image_width = 256;
image_height = 170;
% Focal length in pixels
focal_length = 400;
% Image center coordinates
image_center_x = image_width / 2;
image_center_y = image_height / 2;
% Intrinsic camera calibration matrix K
K = [focal_length, 0, image_center_x; 0, focal_length, image_center_y; 0, 0, 1];
% Display the intrinsic matrix
disp("Part C")
Part C
K
K = 3×3
400 0 128 0 400 85 0 0 1
%*Part D *%
% Create blank image
image = zeros(image_height, image_width);
% Project the 7 points onto the image
points_world = [6.8158 -35.1954 43.0640;
7.8493 -36.1723 43.7815;
9.9579 -25.2799 40.1151;
8.8219 -38.3767 46.6153;
9.5890 -28.8402 42.2858;
10.8082 -48.8164 56.2858;
13.2690 -58.0988 59.1422;]
points_world = 7×3
6.8158 -35.1954 43.0640 7.8493 -36.1723 43.7815 9.9579 -25.2799 40.1151 8.8219 -38.3767 46.6153 9.5890 -28.8402 42.2858 10.8082 -48.8164 56.2858 13.2690 -58.0988 59.1422
points_world2 = transpose(points_world)
points_world2 = 3×7
6.8158 7.8493 9.9579 8.8219 9.5890 10.8082 13.2690 -35.1954 -36.1723 -25.2799 -38.3767 -28.8402 -48.8164 -58.0988 43.0640 43.7815 40.1151 46.6153 42.2858 56.2858 59.1422
points_camera = cW_H(1:3, 1:3) * points_world2 + cW_H(1:3, 4)
points_camera = 3×7
29.4118 30.2095 33.2570 31.8796 33.1022 35.6147 35.7028 -9.8336 -10.3405 -11.9156 -9.7036 -11.0104 -7.1761 -9.1348 90.3273 91.6095 80.4397 94.8716 84.5238 108.5139 118.3390
for i = 1:size(points_camera, 2)
point_camera = points_camera(:, i);
projected_point = K * point_camera;
projected_point = round(projected_point ./ projected_point(3));
x = abs(projected_point(1));
y = abs(projected_point(2));
image(y, x) = 255; % Set pixel value to white
end
% Display the image with white dots
imshow(image);
% Define point indices for drawing lines
point_indices = [1, 2; 2, 3; 3, 4; 4, 1; 5, 6; 6, 7; 7, 8; 8, 5];
% Draw lines between the points
for i = 1:size(point_indices, 1)
point1 = points_camera(:, point_indices(i, 1));
point2 = points_camera(:, point_indices(i, 2));
projected_point1 = K * point1;
projected_point2 = K * point2;
projected_point1 = round(projected_point1 ./ projected_point1(3));
projected_point2 = round(projected_point2 ./ projected_point2(3));
line_points = [projected_point1(1:2)'; projected_point2(1:2)'];
image = insertShape(image, 'Line', line_points, 'LineWidth', 1, 'Color', 'white');
end
Index in position 2 exceeds array bounds. Index must not exceed 7.
% Show the resulting image
imshow(image);

サインインしてコメントする。

### 回答 (1 件)

KSSV 2023 年 7 月 10 日
This line:
point_indices = [1, 2; 2, 3; 3, 4; 4, 1; 5, 6; 6, 7; 7, 8; 8, 5];
should have indices/ values which should be less than or equal to size(points_camera). Note that the dimesnions of size_camera are 3x7. Here in the lines
point1 = points_camera(:, point_indices(i, 1));
point2 = points_camera(:, point_indices(i, 2));
When you extract 7, 8 indices an error will be throws because there is no 8th index in points_camera.
##### 1 件のコメント-1 件の古いコメントを表示-1 件の古いコメントを非表示
Zahryn Martinez 2023 年 7 月 10 日
Here is the updated code, but I am still getting the same error:
% Part A
% Translation vector
translation = [10; -25; 40];
% Euler angles representing the orientation (REPLACE THESE ANGLES)
theta_x = -1; % Angle around X-axis in radians
theta_y = 0.7; % Angle around Y-axis in radians
theta_z = -0.5; % Angle around Z-axis in radians
% Compute the rotation matrices
Rx = [1, 0, 0; 0, cos(theta_x), -sin(theta_x); 0, sin(theta_x), cos(theta_x)];
Ry = [cos(theta_y), 0, sin(theta_y); 0, 1, 0; -sin(theta_y), 0, cos(theta_y)];
Rz = [cos(theta_z), -sin(theta_z), 0; sin(theta_z), cos(theta_z), 0; 0, 0, 1];
% Combine the translation and rotation matrices
cW_H = [Rx * Ry * Rz, translation; 0, 0, 0, 1];
% Display the transformation matrix
disp("Part A")
disp(cW_H)
% Part B
% Compute the inverse transformation matrix
wC_H = inv(cW_H);
% Display the inverse transformation matrix
disp("Part B")
disp(wC_H)
% Part C
% Image size
image_width = 256;
image_height = 170;
% Focal length in pixels
focal_length = 400;
% Image center coordinates
image_center_x = image_width / 2;
image_center_y = image_height / 2;
% Intrinsic camera calibration matrix K
K = [focal_length, 0, image_center_x; 0, focal_length, image_center_y; 0, 0, 1];
% Display the intrinsic matrix
disp("Part C")
disp(K)
% Part D
% Create blank image
image = zeros(image_height, image_width);
% Project the 7 points onto the image
points_world = [6.8158, -35.1954, 43.0640;
7.8493, -36.1723, 43.7815;
9.9579, -25.2799, 40.1151;
8.8219, -38.3767, 46.6153;
9.5890, -28.8402, 42.2858;
10.8082, -48.8164, 56.2858;
13.2690, -58.0988, 59.1422];
points_camera = (cW_H(1:3, 1:3) * points_world' + cW_H(1:3, 4))';
for i = 1:size(points_camera, 1)
point_camera = points_camera(i, :);
projected_point = K * point_camera';
projected_point = round(projected_point ./ projected_point(3));
x = projected_point(1);
y = projected_point(2);
image(y, x) = 255; % Set pixel value to white
end
% Display the image with white dots
disp("Part D")
imshow(image);
% Part E
% Define point indices for drawing lines
point_indices = [1, 2; 2, 3; 3, 4; 4, 1; 5, 6; 6, 7; 7, 8; 8, 5];
% Draw lines between the points
for i = 1:size(point_indices, 1)
point1 = points_camera(point_indices(i, 1), :);
point2 = points_camera(point_indices(i, 2), :);
projected_point1 = K * point1';
projected_point2 = K * point2';
projected_point1 = round(projected_point1 ./ projected_point1(3));
projected_point2 = round(projected_point2 ./ projected_point2(3));
line_points = [projected_point1(1:2)'; projected_point2(1:2)'];
image = insertShape(image, 'Line', line_points, 'LineWidth', 1, 'Color', 'white');
end
% Show the resulting image
disp("Part E")
imshow(image);

サインインしてコメントする。

### カテゴリ

Help Center および File ExchangeImage Arithmetic についてさらに検索

R2023a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by