MATLAB: Create 3D Volume of interest (VOI)

3dimfreehandroisegementationvoi

Hi all,
I am trying to create a 3D volume of interest (VOI), using imfreehand as in the script below. At the moment it's working but i have to draw my ROI at every single slide. Does anybody know whether it is possible to keep the region of the first slide and adjust it in the next slides?
if true
  % 
s = size (MRI1);
for i = 1:s(3);
  A = MRI1(:,:,i);
  imshow (A,[]);
  h = imfreehand(gca);
  BW = createMask(h);
  BWs = imcomplement (BW);
  A(BWs)=0;
  MRIm (:,:,i) = A;
end
end

Best Answer

A thought:
You could use imfreehand on the first slice. imfreehand does not have a 'Position' option that you can set. However, impoly does, so use impoly on the subsequent slices.
I = imread('cameraman.tif');
imshow(I);
hax=gca;
hf = imfreehand(hax);
wait(hf);
for ii = 2:2    
  pos = getPosition(hf);
  %You would create mask etc. before deleting
  delete(hf);    
  hf = impoly(hax,pos);        
end
Can you post an example image? Perhaps there's a way to automate or semi-automate this process so you don't have to repeat this at each slice.
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