FFT

[Gavin Tabor]

John Biddiscombe wrote:
> 
> >I have a 2d array of data in the form of a vtkStructuredPoints
> >object. I want to do an FFT on this (actually, I want to convolve
> >it with various types of filter, but the FFT will do to start with).
> >VTK has various types of FFT algorithm, but they all seem to
> >operate on images - vtkImageFFT for example. Can I input (and output)
> >other forms of structured data for this?
> 
> Yes. StructuredPoints is a subclass of Imagedata - but watch out, the FFT
> stuff doesn't handle complex data properly.

Yes ... having read the manual a bit more carefully, I now
see what the relationship is. Presumably the vtkStructuredPoints
data has to be complex (I currently have it purely real, which is
giving the error "vtkStructuredPointsToImage (0xb0268): ComputeDataType: 
Could not get scalars from input").

I am worried about what you say about the errors here.

Gavin

> 
> (I hope I'm corrected on this point, because I wanted to convolve some
> images and didn't get the results I wanted, so I exported the data to some
> of my older software and did it using that - it was quicker than testing
> the imageFFT extensively) ....
> 
> John B
> 
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-- 

Dr. Gavin Tabor
School of Engineering and Computer Science
Department of Engineering
University of Exeter
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