How to compute centroidal distances

I wanted to compute centroidal distances, by calculating the distance is between the geometric centroid of the segmented object and the brightness centroid of the same.

% Is geometric centroid same as 
s = regionprops(BW,'centroid');

what is brightness centroid

Answer 1

[Matt J]

I assume you mean regionprops(BW, I ,'WeightedCentroid') ? You need an intensity image I, to invoke that option.

Answer 2

[Image Analyst]

You can use regionprops() and sqrt(), like this untested code:

props = regionprops(binaryImage, grayImage, 'Centroid', 'WeightedCentroid');
% Extract centroids into x and y from structure.
centroids = [props.Centroid];
xCentroids = centroids(1:2:end);
yCentroids = centroids(2:2:end);
weightedCentroids = [props.WeightedCentroid];
xWeightedCentroids = weightedCentroids(1:2:end);
yWeightedCentroids = weightedCentroids(2:2:end);
% Compute distances between the centroids and the weighted centroids.
distances = sqrt((xCentroids - xWeightedCentroids) .^2 + (yCentroids - yWeightedCentroids) .^ 2);