ht2ft
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Name
ht2ft - 2d hartley to fourier conversion
Syntax
#include <xite/fht.h>
int ht2ft( IR_BAND inband, IC_BAND outband );
Description
ht2ft converts a Hartley transform to a Fourier transform.
The Fourier transform is given by the Hartley transform
as follows:
F(u,v) = Re{F(u,v)} + j Im{F(u,v)}
= H_e(u,v) - j H_o(u,v)
= (H(u,v) + H(-u,-v))/2 - j (H(u,v) - H(-u,-v))/2
For images with horizontal and vertical even symmetry
H_o(u,v) equals zero, so that
F(u,v) = H_e(u,v) = H(u,v)
Restrictions
bands should have equal size, be quadratic, and have
size some power of two. Currently, only single precision
float values are accepted.
See also
ht2ft(1), fft2d(3), fht2d(3), ft2ht(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: ht2ft.c,v 1.26 1997/05/27 14:48:35 svein Exp $