MAN page from Mandrake Other XITE-3.3-3.i386.rpm
FHTPOWER
Section: C Library Functions (3)
Updated: 16 Mar 1998
Index
NAME
fhtPower - calculate power specter from Hartley transform
SYNTAX
#include <
xite/fht.h>
int fhtPower( IR_BAND inband, IR_BAND outband );
DESCRIPTION
fhtPowercalculates the power spectrum from aHartley transform. The power spectrum is identicalto the power spectrum calculated from the Fouriertransform, and the Hartley transform is significantlyfaster.
The power spectrum is
P(u,v) = [Re{F(u,v)}]^2 + [Im{F(u,v)}]^2
= H_e(u,v)^2 + H_o(u,v)^2
= (H(u,v)^2 + H(-u,-v)^2)/2
For images with horizontal and vertical even symmetry,the power spectrum simplifies to
P(u,v) = ( H(u,v)^2 + H(-u,-v)^2 ) / 2
= H(u,v)^2
RESTRICTIONS
Bands should have equal size. Currently, only singleprecision float values are accepted.
SEE ALSO
fhtPower(1),
fht2d(3),
fft2d(3),
ft2ht(3),
ht2ft(3),
fhtPhase(3)
RETURN VALUE
0 => ok
1 => bad pixel type input
2 => bad pixel type output
3 => bad sizes
AUTHOR
Tor Lønnestad, BLAB, Ifi, UiO
ID
$Id: fhtPower.c,v 1.24 1997/05/27 14:48:33 svein Exp $
Index
- NAME
- SYNTAX
- DESCRIPTION
- RESTRICTIONS
- SEE ALSO
- RETURN VALUE
- AUTHOR
- ID
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