ft2ht
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Name
ft2ht - 2d fourier to hartley conversion
Syntax
#include <xite/fht.h>
int ft2ht( IC_BAND inband, IR_BAND outband );
Description
ft2ht converts a Fourier transform to a Hartley transform.
The Hartley transform is given by the Fourier transform
as follows:
H(u,v) = Re{F(u,v)} - Im{F(u,v)}
= H_e(u,v) + H_o(u,v)
where H_e and H_o are the even and odd parts of H, i.e.
H_e(u,v) = (H(u,v) + H(-u,-v))/2
H_o(u,v) = (H(u,v) - H(-u,-v))/2
For images with horizontal and vertical even symmetry,
H_o(u,v) equals zero, so that
H(u,v) = F(u,v)
Restrictions
bands should have equal size, be quadratic, and have
size some power of two. Currently, only single precision
float and complex values are accepted.
See also
ft2ht(1), fft2d(3), fht2d(3), ht2ft(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: ft2ht.c,v 1.25 1997/05/27 14:48:34 svein Exp $