Is there a way to quantify symmetry in a Image or a CAD file

I have a image or a CAD file such as below where I want to quantify assymetry. In the image shown as can be seen visually the blue line in the right is assymetric in relation to the other blue line versus the orange line. Is there a assymetricty metric which one can think about ? Any inputs here will be valuable.

Answer 1

[Suvansh Arora]

One of the possible ways to quantify the symmetry of an image is to calculate the “Manhattan Norm”.

Please look at the helper function below to calculate the “Manhattan Norm”:

%% Manhattan Norm: To check the Symmetry of Image 
% 
% man_norm = Img - Img_Flipped; 
% 
% man_norm_per_img = (Img - Img_flipped)/size(Img); 

function [man_norm, man_norm_per_img] = imageSymmetry(Img) 
    % Horizontal Flipping the Image 
    Img_Flipped = flip(Img, 2); 
    % Calculate size of image 
    [height, width, dim] = size(Img); 
    % Manhattan Norm calculation 
    man_norm = sum(imabsdiff(Img, Img_Flipped), 'all'); 
    % Manhattan Norm per pixel calculation 
    man_norm_per_img = man_norm / (height * width * dim); 
end 

In order to view the symmetry of an image, call the above helper function:

Img = imread('me.jpg'); 
help imageSymmetry 
[man_norm, man_norm_per_img] = imageSymmetry(Img); 
fprintf('Manhattan norm: %d / per pixel: %d\n', man_norm, man_norm_per_img); 

In order to know more about the functions used, please follow the documentation below:

1. “fprintf" documentation: Display value of variable - MATLAB disp
2. “flip” image in MATLAB: Flip order of elements - MATLAB flip
3. “imabsdiff” to calculate the difference of two images: Absolute difference of two images - MATLAB imabsdiff

I hope the above information helps you.