[vtkusers] vtkImageFFT and vtkImageButterworthLowPass

[Pascale Beliveau]

Hi,

ok, I found my mistake, was not doing ->Update(); sorry to have bothered for
that.

Pascale


On 9/24/08, Pascale Beliveau <beliveaup at gmail.com> wrote:
>
> Hi,
>
>    I have a question concerning FFT transforms. Can it be applied to a 3D
> image?
>
> I am trying to use the butterworth filter of vtk. The volume is fed to
> vtkImageFFT and then I want to apply the butterworth filter. The problem is
> the image is empty right after I feed it to vtkImageFFT (size=0,
> extent=[0,-1,0,-1,0,-1]). I converted my intensity values to float since I
> read that FFT cannot support other types than float or double.
>
> Can anyone help me with this? What else could be a problem with
> vtkImageFFT?
>
> Thanks in advance,
> Pascale
>
> PS: here is my code for reference:
>
>
> vtkImageFFT * FFT = vtkImageFFT::New();
> FFT->SetDimensionality(3);
> FFT->SetInput(VtkImage);
>
>
> vtkImageButterworthLowPass * LPFilter = vtkImageButterworthLowPass::New();
> LPFilter->SetInput(FFT->GetOutput());
> LPFilter->SetOrder(2);
> LPFilter->SetXCutOff(10000);
> LPFilter->SetYCutOff(10000);
> LPFilter->SetZCutOff(10000);
> LPFilter->ReleaseDataFlagOff();
>
> vtkImageData * Result = LPFilter->GetOutput();
>
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