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IDProjectCategoryView StatusDate SubmittedLast Update
0001918ITKpublic2005-06-09 03:262010-11-07 00:31
Assigned ToLuis Ibanez 
PlatformOSOS Version
Product Version 
Target VersionFixed in Version 
Summary0001918: FFT filter does not provide phase images
DescriptionIn Fourier domain filtering, the phase component after FFT is usually discarted. In the ITK (I)FFT filters only absolute images is produced. These images in MRI reflect spatial representation of proton densities, weighted by relaxation processes and pulse sequence setting. In the majority cases only absolute images are viewed by a radiologist.

However, recent image postprocessing techniques utilize also the phase information. Among the others, correction of geometric artifacts in EPI images (B0 field mapping), parallel imaging reconstruction algorithms (GRAPPA, SENSE), correction of partial volume effect in arterial input function in perfusion MRI, susceptibility weighted imaging, velocity measurements, and so on, utilize phase images after FFT.

Therefore, itkVnlFFTComplexConjugateToRealImageFilter should have an option to return: absolute, phase, real, imaginary images.

It is also suggested to rename the filter name. The current name gives an impression that the output of the filter is a real component (of a complex pair) image, while it in fact returns the absolute value.
TagsNo tags attached.
Resolution Date
Sprint Statusbacklog
Attached Files


Luis Ibanez (manager)
2007-09-19 10:37

We will try to do it during WA10
Simon Warfield (developer)
2008-01-23 12:15

There is a set of classes submitted to the Insight Journal that implement complex to complex fourier transforms, and another set of classes for converting between complex representations, and magnitude/phase and real/imaginary representations.

These classes address the need to deal with complex data from `raw' magnetic resonance image acquisitions. [^] [^]
Luis Ibanez (manager)
2010-11-07 00:30

These classes are now in the Review directory.

Luis Ibanez (manager)
2010-11-07 00:31

The new classes in the Code/Review directory provide this behavior.

 Issue History
Date Modified Username Field Change
2007-09-19 10:37 Luis Ibanez Note Added: 0009124
2008-01-23 12:15 Simon Warfield Note Added: 0010236
2010-11-07 00:30 Luis Ibanez Note Added: 0022957
2010-11-07 00:31 Luis Ibanez Sprint Status => backlog
2010-11-07 00:31 Luis Ibanez Note Added: 0022958
2010-11-07 00:31 Luis Ibanez Status assigned => closed
2010-11-07 00:31 Luis Ibanez Resolution open => fixed

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