David,<br><br>You may also find useful the examples:<br><br>/Insight/Examples/Filtering<br><br>FFTDirectInverse2.cxx<br>FFTDirectInverse.cxx<br>FFTImageFilter.cxx<br>FFTImageFilterFourierDomainFiltering.cxx<br><br><br><br>
Regards,<br><br><br> Luis<br><br><br>--------------------------------------------------<br><div class="gmail_quote">On Fri, Jul 24, 2009 at 11:28 AM, C.Cagatay Bilgin <span dir="ltr"><<a href="mailto:bilgic@cs.rpi.edu">bilgic@cs.rpi.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I am not sure which one is faster in ITK but if you<br>
want to see some FFT + inverse FFT example code<br>
here is where you can find it.<br>
<br>
Insight/Testing/Code/Algorithms/itkFFTTest.cxx<br>
<br>
Also the software guide has some discussion about<br>
FFTs in section 6.10. You can download the guide<br>
from<br>
<br>
<a href="http://www.itk.org/ItkSoftwareGuide.pdf" target="_blank">http://www.itk.org/ItkSoftwareGuide.pdf</a><br>
<br>
Regards,<br><font color="#888888">
Cagatay Bilgin</font><div><div></div><div class="h5"><br>
<br>
On Jul 24, 2009, at 10:12 AM, <a href="mailto:svoboda@fi.muni.cz" target="_blank">svoboda@fi.muni.cz</a> wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi,<br>
<br>
I'm a newbie in using ITK and I'd like to ask for help. I'd like to implement fast (efficient) convolution of two large 3D images. I thought I could use "itkConvolutionImageFilter" class but I found out that it does not use FFT, i.e. it performs the naive convolution algorithm using neighbourhood, which is quite slow. Am I right?<br>
<br>
If so, I should probably use convolution theorem, i.e. apply FFT to the input image and also to the kernel, them multiply the results and subsequently apply inverse FFT. Is such a code (written in ITK) available somewhere? Thanks a lot!<br>
<br>
With regards<br>
David<br>
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