I have a problem in using imsegkmeans in a for loop

I’m using several tools in MatLab to segmentate a video I took with a camera. Everything seems to work well, except for the fact that when I ask MatLab to show me the pictures with imsegkmeans they turn out all in different shades of blue and even the binarized image is all blue. However, apparently it’s just a matter of visualization, since I’m using the binarized image to extract height and widht of the object in the video and it works.
Here there is my code:
clear all
close all
clc

% This script performs a DLT transformation of a video each
% 25 frames (each second), plots the mean RGB value of the flame, classifies
% the flame in different cluster and determinates the widht and the height of
% the flame recorded by the camera

v = VideoReader(‘MAH00030_Trim.mp4’);
nFrames = v.NumFrames;

n = 1:25:nFrames;
num = length(n);

% Initialize the level of Red, Green and Blue
meanRedLevels = zeros(num, 1);
meanGreenLevels = zeros(num, 1);
meanBlueLevels = zeros(num, 1);

% Initialize the height and the widht
height = zeros(1,num);
widht = zeros(1,num);

for frame = 1 : 25 : nFrames
% Extract the frame from the movie structure.
thisFrame = read(v, frame);
figure(1)

% Perform the DLT transformation
% Points in the image (in pixels)
pa = [1373 1490]’;
pb = [1359 1240]’;
pc = [2420 1219]’;
pd = [2423 1468]’;

% Refence Points (in mm)
A = [0 200]’;
B = [0 0]’;
C = [840 0]’;
D = [840 200]’;

pin = [pa pb pc pd]; % 2xN matrix of inputs
pout = [A B C D]; % 2xN matrix of output
H = fitgeotrans(pin’,pout’, ‘projective’);
[Iwarp, ref] = imwarp(thisFrame,H);

% Crop the image in order to visualize only the interesting area
croppedImage = imcrop(Iwarp, [230 50 450 350]); %imcrop(Image, [xmin ymin width height])
subplot(2,2,1)
image(croppedImage)
title(‘Video after DLT transformation’)
drawnow;
axis image
axis off
hold on

% Isolate the flame from the background
gImage = rgb2gray(croppedImage);
mask = gImage > 210; % Whatever value will allow to see only the flame
mask = bwareaopen(mask, 1000); % Get rid of any small specks that might be there.
maskedImage = gImage; % Initialize
maskedImage(~mask) = 0; % Zero outside the mask
% Mask the image using bsxfun() function
maskedRgbImage = bsxfun(@times, croppedImage, cast(mask, class(croppedImage)));

% Mean R, G and B level of the flame
meanRedLevels(frame) = mean(mean(maskedRgbImage(:, :, 1)));
meanGreenLevels(frame) = mean(mean(maskedRgbImage(:, :, 2)));
meanBlueLevels(frame) = mean(mean(maskedRgbImage(:, :, 3)));

subplot(2, 2, 2);
hold on;
plot(meanRedLevels, ‘r-‘);
plot(meanGreenLevels, ‘g-‘);
plot(meanBlueLevels, ‘b-‘);
grid on;
title(‘Mean Red, Green and Blue level’)
xlabel(‘Frame [n°]’)
ylabel(‘R, G and B level [-]’)

% Segmentation of the flame with K-means method
nColors = 7;

pixel_labels = imsegkmeans(maskedRgbImage,nColors,’NumAttempts’,3);
subplot(2,2,3)
image(pixel_labels)
title(‘Video divided in 7 clusters’)
axis image off
drawnow;

% Find the height and the widht of the flame
binaryImage = imbinarize(gImage,0.8); % Fit the value of 0.8 in order to visualize only the flame

% Make sure there is only one blob
binaryImage = bwareafilt(binaryImage, 1);

% Label the image
labeledImage = logical(binaryImage);

subplot(2,2,4)
image(binaryImage);
axis off;
axis image;
title(‘Binarized video’)

% Make measurements of bounding box
props(frame) = regionprops(labeledImage, ‘BoundingBox’);
widht(frame) = props(frame).BoundingBox(3);
height(frame) = props(frame).BoundingBox(4);
end

widht = widht(1:25:length(widht))*3.3;
height = height(1:25:length(height))*3.3;

X = 1:length(widht);
Y = 1:length(height);

figure(2)
subplot(1,2,1)
plot(X,widht)
title(‘Widht vs Time’)
xlabel(‘Time [s]’)
ylabel(‘Widht [mm]’)
subplot(1,2,2)
plot(Y,height)
title(‘Height vs Time’)
xlabel(‘Time [s]’)
ylabel(‘Height [mm]’)

The figure that comes out is the following:

However, if I try to run the code with only the clustering it works correctly. Can someone help me?I’m using several tools in MatLab to segmentate a video I took with a camera. Everything seems to work well, except for the fact that when I ask MatLab to show me the pictures with imsegkmeans they turn out all in different shades of blue and even the binarized image is all blue. However, apparently it’s just a matter of visualization, since I’m using the binarized image to extract height and widht of the object in the video and it works.
Here there is my code:
clear all
close all
clc