[Insight-users] anisotropic parmeters for level set segmentation

[Luca Antiga]

Hi Loic,
  in ITK 3.6 it is possible to segment datasets with anisotropic  
voxels without resampling.
This doesn't mean that you'll get perfect segmentations for severely  
anisotropic spacings
(but what's a perfect segmentation in that case?).
In order to try the new feature out, just call filter- 
 >UseImageSpacingOn(), where filter is your
level set filter.
If I understand correctly, you'd like to have propagation, curvature,  
advection weights specified
differently for each axis. This is not possible because those  
coefficients are scalar quantities in
the level set partial differential equation implemented in the filters.
However, one thing you can do is to compute the feature image (prior  
to level sets) using a
Gaussian-based gradient filter (like  
GradientRecursiveGaussianImageFilter) specifying different
sigmas for x, y, z. This will give you something to work on.
Feel free to get back to me if I wasn't exhaustive


Luca



On Apr 15, 2008, at 3:36 PM, BOURGEOIS Loic wrote:
> Hello,
>
> I have to segment MET 3D (Microscopy Electron Tomography) images  
> which are very anisotropic : contrast is quite good along x and y  
> axis but is very low along z axis. So the issue is to tune  
> parameters to the level set (geodesic) along x and y axis different  
> from z axis. Is there possible?
>
> Thank you for your help,
>
> Loic
>
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