How to group the green contour and the yellow contour?

I'm using "imcontour" to get the contour of some image. The resulting image is as follow. Is there any way that I can pick out the green contour together as a group, and the yellow contour together as a group?

Answer 1

[jonas]

Sure, the first output of the imcontour, just like any other contour plot, is a contour matrix . If you understand its structure, then it's quite easy to extract the individual levels. If you upload the image and code I might give it a try.

Here is another question where I first had to parse the contour matrix.

[cliffy]

Thank you very much! I think I got some idea about the format of the matrix, I will give a try!

[jonas]

Cheers! Let me know if you need help.

[cliffy]

Thank you. Do you know how can I store these 2 by n contours automatically. Since every contour have different dimensions, MATLAB doesn't allow me to do that within the For Loop which I tried.

[jonas]

Sure, here is an example. The contours are stored in out and their levels are stored in lvls.

%%Some data
t=1:100;
y=1:100;
z=peaks(100);

%%Get contours
C=contour(t,y,z,'levellist',[2 3]);
cnt=[0];nc=[];idc=[];
while (sum(nc)+cnt)<size(C,2)
  cnt=cnt+1;
  idc=[idc sum(nc)+cnt];
  nc=[nc C(2,idc(end))];
end

%%Save levels and remove the corresponding cols
lvls=C(1,idc);

for j=1:length(idc)-1
out{j} = C(:,idc(j)+1:idc(j+1)-1);
end

[cliffy]

Thank you for the help! It's a nice idea to store matrix in cell. I got it.