kmeans image segmentation
This program gets an image and the desidered number of partitions and finds the means of the different classes and provides a clasified image
(mask).
Cite As
Jose Vicente Manjon-Herrera (2021). kmeans image segmentation (https://www.mathworks.com/matlabcentral/fileexchange/8379-kmeans-image-segmentation), MATLAB Central File Exchange. Retrieved .
Comments and Ratings (119)
MATLAB Release Compatibility
Platform Compatibility
Windows macOS LinuxCategories
Tags
Acknowledgements
Inspired: TACTICS Toolbox
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!Discover Live Editor
Create scripts with code, output, and formatted text in a single executable document.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
Select web siteYou can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)
Error in kmeans1 (line 58)
hc(ind(i))=cc(1);
please help me to correct this error
function [mu,mask]=kmeans(ima,k)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% kmeans image segmentation
%
% Input:
% ima: grey color image
% k: Number of classes
% Output:
% mu: vector of class means
% mask: clasification image mask
%
% Author: Jose Vicente Manjon Herrera
% Email: jmanjon@fis.upv.es
% Date: 27-08-2005
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
ima=imread('1.jpg');
ima=rgb2gray(ima);
subplot(2,2,1),imshow(ima);
k=2; %Number of classes
[~,mask]=kmeans(ima,k);
mask=mat2gray(mask);% convert matrix to image
subplot(2,2,2),imshow(mask);
% check image
ima=double(ima);
copy=ima; % make a copy
% greyLevels=2^8-1; % Number of gray levels
ima=round(ima);
ima=ima(:); % vectorize ima
mi=min(ima); % deal with negative
ima=ima-mi+1; % and zero values
s=length(ima);
% create image histogram
m=max(ima)+1;
h=zeros(1,m);
hc=zeros(1,m);
for i=1:s
if(ima(i)>0)
h(ima(i))=h(ima(i))+1;
end
end
ind=find(h);
hl=length(ind);
% initiate centroids
k=str2double(k);
mu=(1:k)*m/(k+1);
% start process
while(true)
oldmu=mu;
% current classification
for i=1:hl
c=abs(ind(i)-mu);
cc=find(c==min(c));
hc(ind(i))=cc(1);
end
%recalculation of means
for i=1:k
a=find(hc==i);
mu(i)=sum(a.*h(a))/sum(h(a));
end
for i=1:k
if(isnan(mu(i)))
mu(i) = i*m/(k+1);
end
if(mu==oldmu)
break;
end
end
% calculate mask
s=size(copy);
mask=zeros(s);
for i=1:s(1)
for j=1:s(2)
c=abs(copy(i,j)-mi-mu);
a=find(c==min(c));
mask(i,j)=a(1);
end
end
mu=mu+mi-1; % recover real range
end
I got an error and i am trying to use this code as a greenness identification but I don't get any segmented image help me to solve error
Index exceeds the number of array elements (0).
Error in kmeans (line 58)
hc(ind(i))=cc(1);
Thank you
%% to display result
ima=imread('ims1.jpg');
ima=rgb2gray(ima);
subplot(2,2,1),imshow(ima);
k=2; %Number of classes
[mu,mask]=kmeans(ima,k);
mask=mat2gray(mask);% convert matrix to image
subplot(2,2,2),imshow(mask);
I defined k before running the code and put ima=round(ima); before line 32, but still any output, MATLAB is still "busy".
I am a beginner and I am confused how should I interpret the outputs (numbers), is it possible to visualise it on the input image? anyone?
befreo running the code one has to define k i.e. the number of clusters, put ima=round(ima); somewhere before line 32 to round the m value and define a proper image to load
Why no output displayed? How to write code for it along with this current code?
Hello, I'm getting this error while running code
Error using kmeans (line 20)
Not enough input arguments
plz help me .how to see the segmented image
Hi, does anyone know what type of distance measure is being used in this version of k-means?
I see the
c=abs(ind(i)-mu);
within the "current classification" part, is that Manhattan distance?
Also, is
mu=(1:k)*m/(k+1);
the standard way of calculating the centroids? I cannot seem to find a corresponding formula.
Thanks!
This code is running fine, without o/p :-(
but i tried
imshow(mask,[])
imshow(mask)
i didn't get any output.
How to get the segmented image?
how can i see the files??
when i run matlab code to test this segmentation code, i have error sounds like this "Input argument "k" is undefined.How can i define k?"plz help me
when i run matlab code to test this segmentation code, i have error sounds like this "Input argument "k" is undefined."
When I run the matlab code with my .jpg image nothing happens. I tried "imshow(mask)" but I only get a white image. What am I doing wrong ? Is there something to add to the code to get an image output with the result of the segmentation on my image ?
does it return the k centroids from the kmeans clustering as classes?
please help me to see the output.
can u tell how to see this output.Am getting problem while running code..please help me please thanks in advance
why i cant see the code?
Please could anyone tell me how this code works?
Thanks in advance.
Hello sir, I'm getting this error while running your code
Error using kmeans (line 20)
Not enough input arguments.
How can i define k?
How to get the segmented image?
hello,i am realy poor in matlab coding and i dont know how to overcome it.Kmeans in image processing is my homework,too.Still i dont know how i must progress in this:S Please help me
Aswin Raj:
Try 'k=str2double(k);' just before line 46
kmeans
Error using kmeans (line 46)
Not enough input arguments.
L46 : mu=(1:k)*m/(k+1);
how to overcome this error??
When I run the matlab code with my .jpg image nothing happens. I tried "imshow(mask)" but I only get a white image. What am I doing wrong ? Is there something to add to the code to get an image output with the result of the segmentation on my image ?
Oh, I may have missed something, but I may be worth adding a line of say:
ima=round(ima)
on line 33 before the first loop in case you have a matrix of non-integer values.
thanks
Nice, simple, elegant. Cheers.
When I run the matlab code,i have error sounds like this "Input argument "k" is undefined."
in line 42...
pls help me....
Thanks a lot....
i should apply kmeans for the background eliminated image please help me
Why not show users how to visualize the result?
Jessica please use imshow(mask,[]) and check. It should work
When I run the matlab code with my .jpg image nothing happens. I tried "imshow(mask)" but I only get a white image. What am I doing wrong ? Is there something to add to the code to get an image output with the result of the segmentation on my image ?
when i run this code then output of mask is red...why this is happening can anyone help me plz???
when i run matlab code to test this segmentation code, i have error sounds like this "Input argument "k" is undefined."
in line 42...
help me please
where is the segmentation image result??
Thank you.
Excellent!
how do i get to see the code?
How do I implement this code?
Works nicely.
A little word of advice, if I may...
By adding the following two lines (in lines 25-26) you will be capable of dealing non integer inputs also (matrix of double's in my case):
Consider performing rgb2gray to deal with color image inputs as well.
greyLevels=2^8-1; % Number of gray levels
ima=round(greyLevels*ima/max(ima));
Best regards, and keep the good work!
@zheng~~~ plzz help if u r able to understand the code..
very good
very good
where is the statement for loading image by using this code..?? :(
plzz help me how to implement it... i need k-mean clustering deadly for my project work having deadline 15July...
Excellent code, but please, I need to extract the pixels for each classes to calculating some statistical proprities, like mean or std. can you help me please !!
How will we recover the image from the
matrix??
Can anyone help me in how to implement this function on image ??
rubbish
Excellent code, but I came across a problem in this code. Whenever number of clusters specified are more than possible partitions of the image the algorithm got stuck. Here is the solution.
find following line in the given code
if(mu==oldmu) break;end;
now add following lines of code before this line.
for i=1:k,
if(isnan(mu(i)))
mu(i) = i*m/(k+1);
end
end
The problem was occuring when NaN was encountered in centroid computation.
xddfd
The segmented image should be multi colors, based on number of clusters. But I have mask with only one color "always red", Why? I need the segmented image
Help me please...
Doesn't work for me. Tried to run it on the Shepp-Logan phantom:
>> [u,m]=kmeans(phantom(128),4);
??? Attempted to access h(1.2); index must be a positive integer or logical.
Error in ==> kmeans at 35
if(ima(i)>0) h(ima(i))=h(ima(i))+1;end;
i don't how its work with image !! do u have GUI ?
good one..
Can you pls tell me for which k=? did you obtain the result from the image?
there is a problem if there is a total range of grey levels in the image then it is going to be a kind of problem with the solution.
The ımage is complete white?
What shall we do/do not about it?
Nice code...
mahmoud can yo send me the right code?
>Mahmoud Shehadeh I'm gonna send you an email.
k..tq..does it works on the grayscale image..
I'm gonna send you an email.
'Mahmoud'..do you have the corrected code
sorry that was not the right code :)
anyone can help me..why i didn't successfully execute the results..
i'm using the jpeg image.tq
good
trabajo bién
Works fine, thanks!
A bit long when used on high resolution images. But I guess it comes from the kmeans methods itself :)
nice !
Please tell how to execute this code
Please help me how to execute this code in matlab
Thanks, works good.
Dank!
Small bug at line#73, should be:
c=abs(copy(i,j)-mi-mu);
instead of:
c=abs(copy(i,j)-mu); % (mi missing)
Also, performance can be quite improved
it is very beauteful,excellent!
I want to apply kmeans for landsat images pls help me for dat
im doing my final year project in image segmentation based on MRF with ANT COLONY SYSTEM,i dont have any idea ab't that,can u help me,my first module is k-means,can u explain k-mans in depth.
good
good
please help me, how to use this code
Very fast implementation!
It would be great if it is improved to enter more than one input image.
helpful
I need a help from u to solve a paper in image processing
this function works only for integer values of gray level, not for double
Good work, this code very useful for me, but I need method hierarchical clustering for image..., Any idea for me?
No errors, well done. For some applications you might want to use Jose Vicente Manjon-Herrera's EM image segmentation implementation though.
workes good
i m doing my final year project of mini portions segmentation method in face recognition using matlab. may i know how to put my cropped small portions of the face into matrix (eg: 6x9 matrix, where 6 refer to number of photos, n 9 refer to the number of small portions). by the way, i also would like to know how can i compare the matrix column by column in order to get the eigenvalues. n i m new to matlab, so i hope u will help me to clear my doubts. if u have to source code, pls send a copy to me. thanks and really appreciate for your help. Hope can hear from u soon.
Just Perfect. Very fast and great code.
Very good and fast!
K-means is a classic un-supervised classification algorithm. In your code, is there new ideas about k-means? And can you compare the k-means,ISODATA,SOM mathods?
Excellent. Works well.
Excellent!