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fft2d

$ \bigcirc$Name


fft2d Rectangular 2D Fast Fourier Transform




$ \bigcirc$Command Synopsis


fft2d [-i] [-I input_im] [-A output_re] [-B output_im] input_re



-i : to compute inverse FFT

-I input_im : imaginary input (Fimage)

-A output_re : real output (Fimage)

-B output_im : imaginary output (Fimage)

input_re : real input (Fimage)




$ \bigcirc$Function Summary


void fft2d (in_re , in_im , out_re , out_im , i_flag )

Fimage in_re , in_im , out_re , out_im ;

char *i_flag ;




$ \bigcirc$Description


This module computes the Fast Fourier Transform of a 2D input, given by two Fimages (real and imaginary parts). It returns two other Fimages, real and imaginary parts of the Fourier Transform.

Since FFT only applies to images which dimensions are power of 2, the input will be shrinked to proper dimensions if necessary using the fshrink2 module. In this case a warning message will be produced.

The two-dimensional FFT is performed by applying a 1D-FFT on each row of the 2D input, and then on each column.

Several special cases can occur when you use this module as a C subroutine :




$ \bigcirc$See Also


fft1d, fshrink2.

fft2dpol, fft2dview, fftconvol, fftgrad, fftzoom, frandphase, iridgelet, prolate, ridgelet, wiener.


$ \bigcirc$Version 1.1


Last Modification date : Thu Nov 29 20:23:56 2001


$ \bigcirc$Author


Lionel Moisan






next up previous contents index
Next: fft2dpol Up: Reference Previous: tvdenoise   Contents   Index
mw 2004-05-05