How to store the result of areas on every images on loop in one folder to workspace?

i keep getting an error and it only loaded some of the image not all of them, i have like 600+ files but it only loaded for 19 images idk why

clc; clear; close all;

folder_nrml = ('/Users/*/Documents/MATLAB/regionbased_seg/cv/NORMAL');

file_nrml = dir(fullfile(folder_nrml, '*jpeg'));

jumlah_file_nrml = numel(file_nrml);

training_data_nrml = zeros(jumlah_file_nrml);

calc = [];

for l = 1:jumlah_file_nrml

I = imread(fullfile(folder_nrml, file_nrml(l).name));

figure, imshow(I)

bw1= im2bw(I);

bw2 = imfill(bw1,'holes');

s = regionprops(bw2, 'centroid', 'area');

centroids = cat(1, s.Centroid);

area = cat(1, s.Area);

sum_area = sum(area);

hold on

plot(centroids(:, 1), centroids(:,2), 'r*')

[B,L] = bwboundaries(bw2, 'noholes');

[~,l]= bwlabel(bw2,4);

for k = 1:l

boundary = B{k};

plot(boundary(:,2), boundary(:,1), 'y', 'LineWidth', 2)

text(boundary(1,2), boundary(1,1), strcat(['Area = ',num2str(area(k))]), 'Color', 'r', 'FontSize',15, 'FontWeight','bold');

end

calc = [calc;sum_area];

cell_areas(l,:) = {file_nrml(l).name, sum_area};

hold off

end

here are the result and error

Answer 1

[Abhinav Aravindan]

Hi @fayza nayla,

The “bwboundaries” function returns the coordinates of boundary vertices to “B” as a p-by-1 cell array, where "p" is the number of objects and holes. The “bwlabel” function returns the number of connected objects in the input binary image to the variable “l” in your code.

The error you are encountering might be because, for this particular image file, the number of connected objects "l" is greater than the number of boundary vertices returned in "B". Hence, when the value of loop variable "k" increases to a value larger than size of "B", an index greater than the size of the cell array is being accessed resulting in this error.

Additionally, it is to be noted that the same variable “l” is being used twice in the code: as the loop iteration variable and as the output of the “bwlabel” function which can cause an issue.

To resolve this error, you may try replacing the code snippet to plot the boundaries as follows:

for k = 1:size(B, 1)
    boundary = B{k};
    plot(boundary(:,2), boundary(:,1), 'y', 'LineWidth', 2)
    text(boundary(1,2), boundary(1,1), strcat(['Area = ',num2str(area(k))]), 'Color', 'r', 'FontSize',15, 'FontWeight','bold');
end

Please find below the related documentation for your reference:

https://www.mathworks.com/help/images/ref/bwboundaries.html

https://www.mathworks.com/help/images/ref/bwlabel.html