fftMagPhase
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Name
fftMagPhase - 2D Fourier transform and conversion into
magnitude and phase
Syntax
fftMagPhase [<option>...] <inimage> <outimage> [<outimage>]
Description
2D Fourier transform of BIFF image followed by conversion to
linear or logarithmic (decibels) magnitude and/or phase in
radians. The logarithmic mapping of magnitude is according to
out_pix = (log(eps + |in_pix|) + offset) * scale
out_pix = MAX(out_pix, minimum)
Options
-
-fftscale scale
- Scaling of FFT. Default is 1/(xsize*ysize) for forward
transform, 1.0 for inverse transform.
-
-p
- Only phase output. Default: Phase and logarithmic magnitude.
-
-m
- Only magnitude (linear or logarithmic) output.
Default: Phase and logarithmic magnitude.
-
-lin
- Linear magnitude. Default: Logarithmic.
-
-r
- Allow pixeltype of inimage to be double complex. Convert
image to pixeltype complex before applying the Fourier
transform.
Default: Allow only single-precision complex or non-complex
pixeltype for inimage, not double complex. Convert the
image to pixeltype complex before applying the Fourier
transform.
-
-scale scale
- Default value: 20.0.
-
-eps eps
- Default value: 1 / (10 * xsize * ysize)
-
-offset offset
- Default value: -log(eps)
-
-min minimum
- Lower limit for resulting logarithmic magnitude values.
Values below minimum will be set equal to minimum.
Default: No lower limit.
See also
fft2d(1), logarithm(1), phase(1)
Restrictions
Not pixeltype double complex for bands in inimage, unless
option -r is used.
Return value
0 => Ok
1 => Bad number of arguments
2 => Could not read input image
3 => Error in fft routine
4 => Error in absValue routine
5 => Error in logarithm routine
6 => Error in shift_band routine
7 => Error in phase routine
Author
Svein Bøe, BLAB, Ifi, UiO
Id
$Id: fftMagPhase.c,v 1.8 1997/03/17 13:43:30 svein Exp $