FFT

[Charles Law]

The FFT and RFFT works fine.  As a sanity check I put together an example 
that does a correlation operation in the frequence 
domain.  vtk/imaging/TestFFTCorrelation.tcl

The only difference in the result (compared to spatial vtkImageCorrelation) 
is results outside of the boundaries are wrapped to the other side of the 
image.  The price you pay for operations in Frequencey domain.

Charles.



At 02:46 PM 5/11/00 +0100, John Biddiscombe wrote:
> >I am worried about what you say about the errors here.
>
>Well, I wanted to
>
>FFT(data)*Conjugate(FFT(other data))
>and do a straightforward convolution. I failed to get vtk to do it in the
>space of an hour or so and thought - it'd be quicker to do it myself using
>other software. If you get it working, please keep me informed.
>
>ttfn
>
>John B
>
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