[Insight-users] ifft

[Luis Ibanez]

Hi Jesse,

By "normalization" do you mean Intensity Normalization ?

If so, yes, ITK provides multiple filters for preforming
linear operations on the intensities of the image.

You may want to look at the ITK Software Guide

     http://www.itk.org/ItkSoftwareGuide.pdf

and search for the filters:

     IntensityWindowingImageFilter
     ShiftScaleImageFilter
     NormalizeImageFilter


However, I don't quite see how this normalization will
help with the problem of image dimensions that you
describe....



Regards,



    Luis



---------------------
Jesse C Cronce wrote:
> Thanks Carlos, that helped a lot.
> 
> I did that, and what the FFTW outputs is a lot closer to what I really
> want than the VnlFFT was outputting. However, the FFTW inverse fourier
> transform returns an image that is scaled - if I pass in an image that
> is 128 x 512 (complex floats), the output image is 128 x 1022. 
> 
> According to the documentation on the FFTW website, what I want is an
> image that has been normalized (which is apparently what matlab does).
> Does ITK provide an easy way to do this ? Or is it a simple matter of
> moving the pixels around to get the correct image ? Any suggestions
> would be greatly appreciated.
> 
> Thanks,
> JCC
> 
> On Wed, 2005-10-12 at 08:52 -0300, Carlos Santos wrote:
> 
>>Hi,
>>
>>There are some reports of problems with the VnlFFT classes, the
>>suggested solution is using FFTW (http://fftw.org/) instead.
>>See:
>>http://www.itk.org/pipermail/insight-users/2005-July/013900.html
>>for a more thorough discussion.
>>
>>Hope this helps,
>>Carlos
>>
>>On 10/11/05, Jesse C Cronce <croncejc at mrctr.upmc.edu> wrote:
>>
>>>All,
>>>
>>>    Does anyone know if there is an equivalent call to the Matlab call
>>>ifft2 in ITK ?
>>>
>>>When I compare values computed by ifft2 in matlab on an identical matrix
>>>that I put through the itkVnlFFTComplexConjugateToRealImageFilter the
>>>pixel values are extremely different.
>>>
>>>Thanks,
>>>JCC
>>>
>>>_______________________________________________
>>>Insight-users mailing list
>>>Insight-users at itk.org
>>>http://www.itk.org/mailman/listinfo/insight-users
>>>
> 
> 
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