[Insight-users] Inaccuracy in fftw calculation

[Antonio Gómez Barquero]

Inaccuracy in fftw calculation


 

I am calculating the fft of an image which pixels are double with the FFTW
library, for that purpose i am using the library fftw(
<http://www.fftw.org/> http://www.fftw.org/) library in Visual Studio 2008
and using ITK.

 

When I calculate the fft from a double pointer, with the method
‘fftw_plan_dft_c2r_2d’, it makes the calculation but introducing inaccuracy,
it is around +- 0.5


 

I don’t really know what is wrong, maybe the spacing between pixels? The
type of the data used? Did someone have this problem or something similar
before?

 

Many thanks in advanced.

 

Antonio Gómez Barquero

 

Ingeniero de Telecomunicaciones -Becario Investigador asociado a Actividades
de I+D+I 

GTTS ( Grupo de Tratamiento y Teoría de la Señal)[  <http://gtts.upct.es/>
http://gtts.upct.es/]

UPCT (Universidad Politécnica de Cartagena)[  <http://www.upct.es/>
http://www.upct.es/]

 

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