[Insight-developers] changes in level set routines since ITK 3.4 breaks itk-snap

[Luca Antiga]

Hi all,
  I'm responsible for the changes, which were related to the  
extension of level sets to anisotropic voxel spacings.
I'm sorry this difficulty came up.

Let me clarify the issue with ITK_USE_DEPRECATED_LEVELSET_INTERPOLATION.

Before the changes, there was a fudge factor that the authors  
originally introduced in the interpolation of sparse field level sets  
that was intended to help avoiding level set oscillations.
After performing tests and seeing that it wasn't bringing in any  
concrete advantage, the same authors suggested to get rid of that  
fudge factor, however with the possibility of retaining backward  
compatibility. Therefore we introduced the  
ITK_USE_DEPRECATED_LEVELSET_INTERPOLATION flag.

The fudge factor had been never introduced in the parallel version of  
the sparse field, and that's why you don't find any reference to  
ITK_USE_DEPRECATED_LEVELSET_INTERPOLATION in the parallel version.

Without the fudge factor (the new way, with  
ITK_USE_DEPRECATED_LEVELSET_INTERPOLATION=OFF) the serial and  
parallel should behave the same. The old way, not.

I'm compiling SNAP now, I'll try to reproduce the problem and  
investigate on it.


Luca




On Aug 6, 2008, at 2:09 AM, Luis Ibanez wrote:

>
> Hi Casey,
>
> Thanks !
>
> That will help us a lot to track the problem.
>
>
>     Luis
>
>
> ---------------------
> Casey Goodlett wrote:
>> Hi Luis,
>> I submitted a bug report in mantis with the requested information  
>> here http://www.itk.org/Bug/view.php?id=7454
>> Thanks
>> Casey
>> On Tue, Aug 5, 2008 at 5:21 PM, Luis Ibanez  
>> <luis.ibanez at kitware.com <mailto:luis.ibanez at kitware.com>> wrote:
>>     Hi Casey,
>>     Could you please give us a hand by providing a description
>>     of the circumstances in which this error becomes visible ?
>>     E.g. a step-by-step set of instructions will be ideal.
>>     We should then be able to introduce in ITK a new Nightly
>>     test that exercise this same case, and then we can proceed
>>     to fix the problem.
>>      Thanks for any advice,
>>          Luis
>>     ---------------------
>>     Bill Lorensen wrote:
>>         Casey,
>>         Snap is an important ITK customer. We'll work with you to  
>> figure
>>         out the issues.
>>         Bill
>>         On Tue, Aug 5, 2008 at 5:15 PM, Casey Goodlett
>>         <gcasey at sci.utah.edu <mailto:gcasey at sci.utah.edu>> wrote:
>>             It's a functionality change.
>>             On Tue, Aug 5, 2008 at 3:14 PM, Bill Lorensen
>>             <bill.lorensen at gmail.com  
>> <mailto:bill.lorensen at gmail.com>>
>>             wrote:
>>                 Is this a compilation error or functionality change?
>>                 On Tue, Aug 5, 2008 at 5:06 PM, Casey Goodlett
>>                 <gcasey at sci.utah.edu <mailto:gcasey at sci.utah.edu>>
>>                 wrote:
>>                     Hi,
>>                     I have recently compiled itk-snap 1.6.0.1
>>                     <http://1.6.0.1> against the latest version of
>>                     ITK,
>>                     and the automatic segmentation routines in  
>> SNAP no
>>                     longer behave
>>                     correctly.
>>                     When initializing the segmentation routine with a
>>                     bubble, the bubble
>>                     does
>>                     not get correctly converted into a label map  
>> using
>>                     newer versions of
>>                     ITK,
>>                     and the level set evolution does not behave
>>                     correctly.  Going back to
>>                     ITK
>>                     3.4 fixes the problem.
>>                     I've noticed that there were changes made to the
>>                     level set routines in
>>                     ITK
>>                     with respect to bug 0006156 (
>>                     http://public.kitware.com/Bug/view.php?id=6156
>>                     ).  I've checked out CVS of ITK before and after
>>                     these changes and can
>>                     confirm that the problem came about in ITK  
>> between
>>                     2008-03-01 and
>>                     2008-03-06.
>>                     I tried toggling the
>>                     ITK_DEPRECATED_LEVELSET_INTERPOLATION flag in the
>>                     cmake
>>                     config but there was no effect on the problem.
>>                     I'm unsure how to solve the problem so that  
>> snap can
>>                     be used against the
>>                     current version of ITK.  Can someone explain  
>> how the
>>                     behavior of the
>>                     level
>>                     set filters changed?
>>                     Thank you
>>                     --
>>                     Casey Goodlett
>>                     _______________________________________________
>>                     Insight-developers mailing list
>>                     Insight-developers at itk.org
>>                     <mailto:Insight-developers at itk.org>
>>                     http://www.itk.org/mailman/listinfo/insight- 
>> developers
> _______________________________________________
> Insight-developers mailing list
> Insight-developers at itk.org
> http://www.itk.org/mailman/listinfo/insight-developers