I want to segment my leaf image with 4 clusters. but shows the error: Attempt to grow array along ambiguous dimension. Error in Detect (line 46) colors(rgb_label ~= k) = 0;

here's my code:

clc

close all

clear all

[filename, pathname] = uigetfile({'*.*';'*.bmp';'*.jpg';'*.gif'}, 'Pick a Leaf Image File');

I = imread([pathname,filename]);

I = imresize(I,[256,256]);

figure, imshow(I);

title('Query Leaf Image');

I = imadjust(I,stretchlim(I));

I_Otsu = im2bw(I,graythresh(I));

I_HIS = rgb2hsi(I);

cform = makecform('srgb2lab');

lab_he = applycform(I,cform);

ab = double(lab_he(:,:,2:3));

nrows = size(ab,1);

ncols = size(ab,2);

ab = reshape(ab,nrows*ncols,2);

num=4;

nColors = num;

[cluster_idx cluster_center] = kmeans(ab,nColors,'distance','sqEuclidean', ...

'Replicates',4);

pixel_labels = reshape(cluster_idx,nrows,ncols);

segmented_images = cell(1,nColors);

% Create RGB label using pixel_labels

rgb_label = repmat(pixel_labels,[1,1,nColors]);

for k = 1:nColors

colors = I;

colors(rgb_label ~= k) = 0;

segmented_images{k} = colors;

end

figure, subplot(4,1,1);

imshow(segmented_images{1});

title('Cluster 1');

subplot(4,1,2);

imshow(segmented_images{2});

title('Cluster 2');

subplot(4,1,3);

imshow(segmented_images{3});

title('Cluster 3');

subplot(4,1,4);

imshow(segmented_images{4});

title('Cluster 4');