[Insight-users] Re: Gradient Vector Flow Image Filter compile error

[Quan Chen]

Sorry, I just checked the example (I didn't be able to find it under
example dir, it was under Testing dir).  And I see the different way
that this filter should be used.  However I still have question.

The testing example puts this way:

typedef itk::GradientVectorFlowImageFilter<myGradientImageType,
myGradientImageType>
                                              myGVFFilterType;

  typedef itk::GradientImageFilter<myImageType, double, double>
                                              myGFilterType;

So it want the inputimage and outimage of the GradientVectorFlow the
same format?  However, the filter itself should expected a edge image,
which is not gradient image itself.  In the testing example, we have

myGFilterType::Pointer gfilter = myGFilterType::New();
myGVFFilterType::Pointer m_GVFFilter = myGVFFilterType::New();

  m_GVFFilter->SetInput(gfilter->GetOutput());

Now the output of the gfilter (myGFilterType) should be myImageType,
right?  So the GVFFilter will doing some conversion?  Why this filter
is designed this way?