www.pudn.com > fcmthresh.zip > fcmthresh.m

function [bw,level]=fcmthresh(IM,sw) 
%FCMTHRESH Thresholding by 3-class fuzzy c-means clustering 
%  [bw,level]=fcmthresh(IM,sw) outputs the binary image bw and threshold level of 
%  image IM using a 3-class fuzzy c-means clustering. It often works better 
%  than Otsu's methold which outputs larger or smaller threshold on 
%  fluorescence images. 
%  sw is 0 or 1, a switch of cut-off position. 
%  sw=0, cut between the small and middle class 
%  sw=1, cut between the middle and large class 
% 
%  Contributed by Guanglei Xiong (xgl99@mails.tsinghua.edu.cn) 
%  at Tsinghua University, Beijing, China. 
 
% check the parameters 
if (nargin<1) 
    error('You must provide an image.'); 
elseif (nargin==1) 
    sw=0; 
elseif (sw~=0 && sw~=1) 
    error('sw must be 0 or 1.'); 
end 
 
data=reshape(IM,[],1); 
[center,member]=fcm(data,3); 
[center,cidx]=sort(center); 
member=member'; 
member=member(:,cidx); 
[maxmember,label]=max(member,[],2); 
if sw==0 
    level=(max(data(label==1))+min(data(label==2)))/2; 
else 
    level=(max(data(label==2))+min(data(label==3)))/2; 
end 
bw=im2bw(IM,level);