[Insight-developers] LabelOverlapImageFilter Assert issue

[Nicholas Tustison]

That’s a good question, Brad.  When I wrote this filter, I started with the
LabelStatisticsImageFilter since it was, in my mind, closest to what I 
wanted to write.  That override is simply leftover from what I copied
originally: 

https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Filtering/ImageStatistics/include/itkLabelStatisticsImageFilter.hxx#L43

It certainly is not a result of me trying to do something sophisticated.  I
didn’t know any better so I just left it in.  The same could probably be 
said for anything questionable that you might find in this class.

Nick



On Mar 8, 2014, at 3:55 PM, Bradley Lowekamp <blowekamp at mail.nih.gov> wrote:

> Nick,
> 
> I am trying to add LabelOverlapImageFilter to SimpleITK. It's failing one of my test in SimpleITK. At this is the section:
> 
>  itk::simple::Image smallImage( 1,1,1,itk::simple::sitkUInt8 );
>  itk::simple::Image largeImage( 10,10,10,itk::simple::sitkUInt8 );
>  itk::simple::Image smallShortImage( 1,1,1,itk::simple::sitkUInt16 );
>  try
>    {
>    // Try executing with different size images.
>    // This will either work or throw an exception, either is OK. So
>    // this is here just to make sure that the behavior does not cause
>    // undefined behavior such as segfault, or other errouneos behavior.
>    filter.Execute ( largeImage, smallImage );
>    } catch (... )
>    { }
> 
> http://open.cdash.org/testDetails.php?test=240179118&build=3246420
> 
> This is causing a miss-matched region assert to fail in the iterator:
> https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Core/Common/include/itkImageConstIterator.h#L208
> 
> During the construction of the iterator here:
> https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Filtering/ImageStatistics/include/itkLabelOverlapMeasuresImageFilter.hxx#L142
> 
> There is also a non-standard GenerateInputRequestedRegion:
> https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Filtering/ImageStatistics/include/itkLabelOverlapMeasuresImageFilter.hxx#L39
> 
> The normal implementation of this method requests all inputs to have the same ImageRegion. This normally then triggers exceptions with the requested region not able to be generated from the pipeline.
> 
> I don't immediately see the reason why the GenerateInputRequestedRegion was overridden, the default should work ok. Do you know why?
> 
> Thanks,
> Brad