[Insight-users] Degenerated volumes question

[Miller, James V (Research)]

Benjamin,

If you want to try something, change line 128 of
itkMorphologyImageFilter.txx
from 

    while ( ! b_iter.IsAtEnd() )

to 

    while ( ! o_iter.IsAtEnd() )

and see if this fixes your crashes.  If you have revision 1.15 of
itkImageConstIterator.h then this may fix your problem.  Prior to revision
1.15 of itkImageConstIterator.h we had a bug when a region had no pixels in
it. 

Let us know if this works for you and I'll change the code in the
repository.

Jim



> -----Original Message-----
> From: Miller, James V (Research) [mailto:millerjv at crd . ge . com]
> Sent: Tuesday, August 26, 2003 9:41 AM
> To: 'Benjamin King'; ITK
> Subject: RE: [Insight-users] Degenerated volumes question
> 
> 
> These filters do handle boundary conditions. The filters 
> break an image up 
> into a series of small regions, one that has no boundary 
> conditions and N
> that
> have boundary conditions.
> 
> With such a small region, I am guessing some of the regions 
> are empty and 
> causing a problem. So I don't think this is a problem with a 
> degenerate
> volume 
> (a volume with a single slice) but rather a region that has no pixels.
> 
> Can you provide more information about the specifics? For a particular
> crash,
> what was the region size? What filter were you trying to run? 
> What size of a
> 
> structuring element were you trying to use?
> 
> Without this information, I cannot focus on where the bug 
> will be.  Just
> saying
> you have a bug with small regions in ITK is not a very graceful way to
> report a bug.
> 
> 
> 
> > -----Original Message-----
> > From: Benjamin King [mailto:king . benjamin at mh-hannover . de]
> > Sent: Tuesday, August 26, 2003 10:19 AM
> > To: ITK
> > Subject: [Insight-users] Degenerated volumes question
> > 
> > 
> > Hi all,
> > 
> > I'm working on a program that takes a labled volume and then 
> > finds the 
> > minimal itk::Region that contains all voxels with a certain 
> > label. I often 
> > get very small regions i.e. with a size of (1,8,4). 
> > Extracting them with 
> > itk::RegionOfInterestImageFilter and afterwards applying 
> > morphological 
> > operations often (but not always) results in segmentation faults.
> > 
> > Padding the small regions will probably fix this but I was 
> > wondering if it 
> > would be possible to hide this in the MorphologyImageFilter 
> > class. After 
> > all these filters have to handle boundary conditions anyway, 
> > haven't they?
> > 
> > I also think that a segmentation fault is not a very graceful 
> > way to handle 
> > degenerated volumes.
> > 
> > 
> > Best regards,
> >   Benjamin
> > 
> > -- 
> > Benjamin King
> > Institut fur Medizinische Informatik
> > Medizinische Hochschule Hannover
> > Tel.: +49  511  532-2663
> > _______________________________________________
> > Insight-users mailing list
> > Insight-users at itk . org
> > http://www . itk . org/mailman/listinfo/insight-users
> > 
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