comp1=data(:,:,1);
p=1;
for i=1:256 for j=1:320
if(isnan(comp1(i,j))==0)
    xcomp1(p)=j;
    ycomp1(p)=i;
    p=p+1;
end; end; end;

plot(xcomp1,ycomp1,'.');
test=kmeans([xcomp1' ycomp1'],6);
for i=1:6
    nindex=find(test==i);
    figure;
    plot(xcomp1(nindex),ycomp1(nindex),'.');
end