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/* im_c2amph.c ... convert to polar
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 12/02/1990
* Modified on : 09/05/1990
* 15/6/93 JC
* - stupid stupid includes and externs fixed
* - I have been editing for 1 1/2 hours and I'm still drowning in
* rubbish extetrnshh
* 13/12/94 JC
* - modernised
* 9/7/02 JC
* - degree output, for consistency
* - slightly better behaviour in edge cases
* 27/1/10
* - modernised
* - gtk-doc
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
#define loop(TYPE) { \
TYPE *p = (TYPE *) in; \
TYPE *q = (TYPE *) out; \
int x; \
\
for( x = 0; x < n; x++ ) { \
double re = p[0]; \
double im = p[1]; \
double am, ph; \
\
am = sqrt( re * re + im * im ); \
ph = im_col_ab2h( re, im ); \
\
q[0] = am; \
q[1] = ph; \
\
p += 2; \
q += 2; \
} \
}
/* c2amph buffer processor.
*/
static void
buffer_c2amph( void *in, void *out, int w, IMAGE *im )
{
int n = w * im->Bands;
switch( im->BandFmt ) {
case IM_BANDFMT_DPCOMPLEX: loop(double); break;
case IM_BANDFMT_COMPLEX: loop(float); break;
default:
g_assert( 0 );
}
}
/**
* im_c2amph:
* @in: input image
* @out: output image
*
* Convert a complex image from rectangular to polar coordinates. Angles are
* expressed in degrees.
*
* See also: im_c2rect(), im_abs().
*
* Returns: 0 on success, -1 on error
*/
int
im_c2amph( IMAGE *in, IMAGE *out )
{
if( im_check_uncoded( "im_c2amph", in ) ||
im_check_complex( "im_c2amph", in ) ||
im_cp_desc( out, in ) )
return( -1 );
if( im_wrapone( in, out,
(im_wrapone_fn) buffer_c2amph, in, NULL ) )
return( -1 );
return( 0 );
}