How do I find the centre of gravity for an irregular shape?

I have given the marked coordinates and region of interest in which I would like to find the centre of gravity for, please help me.

[Jan]

In which format are the input data given?

[Sudev Parthiban]

It is an ultrasound image it is in .mat format... This is my code:

clc
clear
close all
cd('C:\Users\ADMIN\Desktop\Sudev\Objective 1')

load('ROI1.mat');  %Load data from file  

figure(1); clf;
subplot(1,2,1);
imshow(paveikslas,[])
paveikslas(1:200,1:200,:) = 0;

figure(1); clf;
subplot(1,2,1);
imshow(paveikslas,[])
hold on
plot(x_poly, y_poly,'r','LineWidth',2)
title('Overlap of ROI on Bscan')
subplot(1,2,2);
plot(x_poly); hold on;
plot(y_poly,'-r');
title('Coordinates of ROI')

    figure(2)
plot(x_poly, y_poly,'r','LineWidth',2)
axis equal
title('ROI to be calculated for Center and Axis')

Answer 1

[Bruno Luong]

You can get the coordinates of the centroid if you have a boundary coordinates of a polygonal region:

[xc,yc] = polygoncentroid(x_poly,y_poly)

using this function

function [xc,yc] = polygoncentroid(x,y)
xn = circshift(x,-1);
yn = circshift(y,-1);
A = x.*yn-xn.*y;
a = 3*sum(A);
xc = sum((x+xn).*A)/a;
yc = sum((y+yn).*A)/a;
end

[Sudev Parthiban]

Thank you it worked for me

Answer 2

[Kaustav Bhattacharya]

Refer this link. It might help. https://in.mathworks.com/matlabcentral/answers/339583-hellou-could-i-ask-for-help-finding-the-center-of-gravity-of-the-object

[Sudev Parthiban]

That is for a binary image but mine is not.

[Jan]

@Sudev: I ask again: In which format is the image given? It does not matter, that it has been saved as MAT file, but the type and dimensions of the data are important. Please do not explain, what the image is not, but what it is.

[Sudev Parthiban]

It is in DICOM format.

[Jan]

The DICOM format is a file format. You have loaded the data from a MAT file. Therefore I think, that "DICOM format" is neither possible, nor does it explain, how the data are represented. All we know currently is that your data are not a binary image. Please provide any explicit details about the input. It would be inefficient if the readers guess, which data you have.

What do you exactly get for:

data = load('ROI1.mat')

Loading data directly into the workspace is prone to bugs. Prefer to catch the data in a variable like in my example.