[Insight-users] problems using itkVectorResampleImageFilter

[Luis Ibanez]

Tomas,


This is a tricky one....

The  VectorInterpolateImageFunction class assumes that the
output of the computation is going to be stored in a FixedArray
and therefore it needs to know the dimension at *compile time*.

The VariableLengthVector class doesn't know its dimension at
compile time. In fact, it can change at run time.

We could modify the VectorInterpolateImageFunction in order to
use as output a NumericTrait of the pixel type from the input
image.

Something like (pseudocode)

   NumericTraits< typename InputImage::PixelType >::RealType


The NumericTraits::RealType  of VariableLengthVector
is available in the file:

   Insight\Code\Common\itkNumericTraitsVariableLengthVectorPixel.h


---

That being said, I think a while ago Karthik reworked the
InterpolateImageFunction itself so that it could manage a
VectorImage. That means that you could use the "normal"
ResampleImageFilter in order to process a VectorImage


(this is just a vague memory, and it is too early in the
   morning to assure you that this actually happened...)



Please enter a report for this problem in the BugTracker.

     http://public.kitware.com/Bug/my_view_page.php

We should start by adding a test to excercise resampling
on a Vector image (different types of them eg. image of
RGB pixels, image of Vectors, and a VectorImage<float,dim> ).



    Thanks


       Luis


---------------------
Tomáš Kazmar wrote:
> It is kind of silly because there is already Size() and
> GetNumberOfElements() that return the same information
> and it is called statically from the filter:
> 
>  const unsigned int numberOfComponents = 
> PixelType::GetNumberOfComponents();
> 
> ...but it seems it would make it work:)
> 
> Tomas
> 
> # It may be silly, but would it be possible to add a  # 
> GetNumberOfComponents() in the VariableLengthVector class, which  # 
> return the number of components at runtime ?
> # # Gaëtan
> # # # Le 12 sept. 07 à 21:26, Dan Mueller a écrit :
> # # > Hi Yogesh,
> # >
> # > It seems the VectorResampleImageFilter requires a pixel type which has
> # > the number of dimensions defined at compile time, not run-time: any
> # > type derived from FixedArray should work (eg. Vector,
> # > CovariantVector). I'm not exactly sure why -- it's a little outside my
> # > realm of knowledge. Any other takers?
> # >
> # > It should be possible to implement a templated function which can
> # > delegate to a filter with the correct number of dimensions at
> # > run-time:
> # >    Eg. see http://public.kitware.com/pipermail/insight-users/2002- # 
>  > June/000513.html
> # >
> # > HTH
> # >
> # > Cheers, Dan
> # >
> # > On 13/09/2007, Yogesh Rathi <yogesh.rathi at gmail.com> wrote:
> # >> Anybody noticed compilation problems when using  # >> 
> itkVectorResampleImageFilter
> # >> ?
> # >>
> # >> I am getting the following errors when I use this filter:
> # >>
> # >> itkVectorInterpolateImageFunction.h:35: error: 'Dimension'
> # >> is not a member of 'itk::VariableLengthVector<float>'
> # >>
> # >> error: no matching function for call to
> # >> 'itk::VectorResampleImageFilter<itk::VectorImage<float,
> # >> 3u>, itk::VectorImage<float, 3u>,
> # >> double>::SetTransform # >> 
> (itk::SmartPointer<itk::CenteredAffineTransform<float,
> # >> 3u> >&)'
> # >>
> # >> itkVectorResampleImageFilter.h:120: note: candidates are: void
> # >> itk::VectorResampleImageFilter<TInputImage, TOutputImage,
> # >> TInterpolatorPrecisionType>::SetTransform(const
> # >> itk::Transform<TInterpolatorPrecisionType,
> # >> 
> itk::VectorResampleImageFilter<TInputImage,TOutputImage,TInterpolator # 
>  >> PrecisionType>::ImageDimension,
> # >> 
> itk::VectorResampleImageFilter<TInputImage,TOutputImage,TInterpolator # 
>  >> PrecisionType>::ImageDimension>*)
> # >> [with TInputImage = itk::VectorImage<float, 3u>, TOutputImage =
> # >> itk::VectorImage<float, 3u>, TInterpolatorPrecisionType = double]
> # >>
> # >> itkVectorResampleImageFilter.txx:175: error:
> # >> 'GetNumberOfComponents' is not a member of
> # >> 'itk::VariableLengthVector<float>'
> # >>
> # >> Thanks in advance,
> # >>
> # >> Yogesh
> # > _______________________________________________
> # > Insight-users mailing list
> # > Insight-users at itk.org
> # > http://www.itk.org/mailman/listinfo/insight-users
> # # --
> # Gaëtan Lehmann
> # Biologie du Développement et de la Reproduction
> # INRA de Jouy-en-Josas (France)
> # tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
> # http://voxel.jouy.inra.fr
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