itk::RelabelComponentImageFilter::GetSizeOfObjectInPhysicalUnits signature

cg2 · October 1, 2024, 3:07pm

Hi,

After the detection of of a signedness comparison error during the compilation of RelabelComponentImageFilter:

ITK-5.2/itkRelabelComponentImageFilter.h:228:24: error: comparison of integer expressions of different signedness: ‘itk::RelabelComponentImageFilter<itk::Image<short int, 3>, itk::Image<short int, 3> >::LabelType’ {aka ‘short int’} and ‘const SizeValueType’ {aka ‘const long unsigned int’} [-Werror=sign-compare]
  228 |     if (obj > 0 && obj <= m_NumberOfObjects)

I realized that the GetSizeOfObjectInPhysicalUnits signature expects a LabelType=InputPixelType parameter. Does it make sense since we are accessing a std::vector<float> by index? I would have expected something like ObjectSizeType or itk::IdentifierType…

I’m sure I’m missing something. Thanks for your help.

Best Regards,

dzenanz · October 1, 2024, 3:20pm

You are right, that should be SizeValueType, as per:

github.com

InsightSoftwareConsortium/ITK/blob/3b04ad1b377c6d5d77a2c1f454c363eab8197340/Modules/Segmentation/ConnectedComponents/include/itkRelabelComponentImageFilter.h#L284


      
          
              RelabelComponentObjectType &
              operator+=(const RelabelComponentObjectType & other)
              {
                this->m_SizeInPixels += other.m_SizeInPixels;
                return *this;
              }
            };
          
          private:
            SizeValueType  m_NumberOfObjects{ 0 };
            SizeValueType  m_NumberOfObjectsToPrint{ 10 };
            SizeValueType  m_OriginalNumberOfObjects{ 0 };
            ObjectSizeType m_MinimumObjectSize{ 0 };
            bool           m_SortByObjectSize{ true };
          
            std::mutex m_Mutex{};
          
            using MapType = std::map<LabelType, RelabelComponentObjectType>;
            MapType m_SizeMap{};

Can you make a PR?

cg2 · October 1, 2024, 7:41pm

github.com/InsightSoftwareConsortium/ITK

COMP: Fix compilation issue when using RelabelComponentImageFilter

InsightSoftwareConsortium:master ← kenavolic:fix_relabel_compilation_issue

opened 07:39PM - 01 Oct 24 UTC

kenavolic

+2 -2

* Update parameter type to reflect underlying container indexing Fixes #4865 …   ## PR Checklist There is a public API change as the parameter type is changed. - [ ] No [API changes](https://github.com/InsightSoftwareConsortium/ITK/blob/master/CONTRIBUTING.md#breaking-changes) were made (or the changes have been approved) - [x] No [major design changes](https://github.com/InsightSoftwareConsortium/ITK/blob/master/CONTRIBUTING.md#design-changes) were made (or the changes have been approved) Refer to the [ITK Software Guide](https://itk.org/ItkSoftwareGuide.pdf) for further development details if necessary.

Niels_Dekker · October 1, 2024, 10:43pm

Thanks for addressing this issue @cg2.

I’m not entirely sure, but my guess it that LabelType is usually an unsigned integer type. I mean, intuitively you would use natural numbers to label objects, 1, 2, 3, … right? So then the label image ( itk::Image) would almost naturally have an unsigned integer type as pixel type.

That might explain why these errors did not occur before. But I’m just guessing.