How can I delete data from my table if two centroids from regionprops are the same?

I am analyzing spheroid formations on images of nerve tissue. My microscope saves multiple images from the same time, visualizing only some part of the tissue. Below is the code that is working for my images to identify the spheroids. However, since some images overlap with others, so does the regionprops. I want to be able to quantify the spheroid formation across all my images without counting some spheroids twice.

In the following code, I want my table "Testing" where I am saving all the information of regionprops to clear the data if two centroids are in the same position or relatively close to each other, and keep the largest spheroid.

%MATLAB CODE TO IMPORT FOR REGIONPROPS MULTIPLE IMAGES

clear;
clc;

n = 20; %assuming number of images is 20
stats = cell(n, 1);
for k = 15:n  %Right now I am interested on starting on image #15-20 just for testing purposes
    stats{k} = analyse(k);
end

Testing = [stats{15}.large_Stats;stats{16}.large_Stats;stats{17}.large_Stats;stats{18}.large_Stats;stats{19}.large_Stats;stats{20}.large_Stats];

%Here is where I want a code for my table to be take out double data based
%on centroid position


function out = analyse(k)
%MATLAB CODE FOR REGIONPROPS
    filename = "45_min" + k + ".png";
    A = imread(filename);
    figure,imshow(A)
    [~,BW,~] = imsplit(A);
    %figure,imshow(BW);
    BW = imsharpen(BW);
    BW = imreducehaze(BW);
    BW = im2bw(BW,0.85);
    figure,imshow(BW)
    stats = regionprops(BW,"all");
    n=1;
    for i = 1:length(stats)
        out.area(i)= stats(i).Area;
        out.perimeter(i) = stats(i).Perimeter;
        out.circularity(i)= stats(i).Circularity;
        out.centroid{i}= stats(i).Centroid;
        out.majoraxislength(i) = stats(i).MajorAxisLength;
        out.minoraxislength(i) = stats(i).MinorAxisLength;
        if out.circularity(i)~=Inf && out.circularity(i)>0.44 && out.area(i)>120
            out.large_areas(n) = out.area(i);
            out.large_perimeter(n) = out.perimeter(i);
            out.large_circularity(n) = out.circularity(i);
            out.large_centroid(n) = out.centroid(i);
            out.large_majoraxislength(n) = out.majoraxislength(i);
            out.large_minoraxislength(n) = out.minoraxislength(i);
            n= n+1;
        end 
    end
    out.centers = out.large_centroid';
    out.centers = cell2mat(out.centers);
    out.large_minoraxislength = out.large_minoraxislength';
    out.large_majoraxislength = out.large_majoraxislength';
    out.large_Stats = table(out.large_areas',out.large_perimeter', out.large_centroid', out.large_circularity', out.large_majoraxislength, out.large_minoraxislength);
    out.large_Stats.Properties.VariableNames(1:4) = {'Area' 'Perimeter' 'Centroid' 'Circularity'};
    out.diameters = mean([out.large_majoraxislength out.large_minoraxislength],2);
    out.radii = out.diameters/2;
    hold on
    viscircles(out.centers,out.radii);
    hold off
end

Answer 1

[Shreeya]

Hi @Francisco

I understand that you want to delete the spheroid data in the table “stats” which have the same centroid values. Kindly use the “unique” function for this:

[~,idx] = unique(stats.centroid)
stats = stats(idx,:)

Please refer to the documentation to know more about the function: https://www.mathworks.com/help/images/ref/regionprops.html

I hope this resolves your problem!

Answer 2

[Image Analyst]

Chances are low that you will ever have the same centroid location exactly, out to 16 decimal places. I suggest you use ismembertol to find locations that are within one pixel unit of each other.