[Insight-users] How to get sub voxel values using BSpline

[Luis Ibanez]

Hi Rashed,

Here is what you may want to do:

0) typedef
      BSplineInterpolateImageFunction<
        ImageType,
        CoordinateRepresentationType >
                    BSplineInterpolatorType;

1) Instantiate a BSplineInterpolator

2) Put the coordinates of your point in an
    itk::Point< CoordinateRepresentationType > type

3) Call interpolator->Evaluate( point );

4) Call interpolator->EvaluateDerivative( point );

In this context you no longer need the
DerivativeImageFilter.



   Regards,


      Luis


----------------
rashedk wrote:
> Hi ITK Experts, 
> 
> I would like to compute sub-voxel values using BSpline interpolation. To be
> more specific, I am using the DerivativeImageFilter to compute the image
> gradient, and would like to compute the gradient at sub-voxel positions. 
> 
> I looked in the ITK software guide, but it seems like all interpolation
> examples are tied with registration where interpolators are assigned to the
> filter using a SetInterpolator function. But I cant do the same with
> DerivativeImageFilter.
> 
> Thanks in advance, 
> Rashed