libvips/libsrc/arithmetic/im_sign.c

163 lines
3.3 KiB
C

/* @(#) Find the unit vector in the direction of the pixel.
* @(#)
* @(#) int im_sign(in, out)
* @(#) IMAGE *in, *out;
* @(#)
* @(#) Returns 0 on success and -1 on error
* @(#)
*
* 9/7/02 JC
* - from im_cmulnorm
*/
/*
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 <assert.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
#define sign_complex( IN, OUT ) \
{ \
IN *p = (IN *) in; \
OUT *q = (OUT *) out; \
int x; \
\
for( x = 0; x < n; x++ ) { \
IN re = p[0]; \
IN im = p[1]; \
double fac = sqrt( re * re + im * im ); \
\
p += 2; \
\
if( fac == 0.0 ) { \
q[0] = 0.0; \
q[1] = 0.0; \
} \
else { \
q[0] = re / fac; \
q[1] = im / fac; \
} \
\
q += 2; \
} \
}
#define sign( IN, OUT ) \
{ \
IN *p = (IN *) in; \
OUT *q = (OUT *) out; \
int x; \
\
for( x = 0; x < n; x++ ) { \
IN v = p[x]; \
\
if( v > 0 ) \
q[x] = 1; \
else if( v == 0 ) \
q[x] = 0; \
else \
q[x] = -1; \
} \
}
/* sign buffer processor.
*/
static void
buffer_sign( void *in, void *out, int w, IMAGE *im )
{
int n = w * im->Bands;
switch( im->BandFmt ) {
case IM_BANDFMT_UCHAR:
sign( unsigned char, signed char );
break;
case IM_BANDFMT_CHAR:
sign( signed char, signed char );
break;
case IM_BANDFMT_USHORT:
sign( unsigned short, signed char );
break;
case IM_BANDFMT_SHORT:
sign( signed short, signed char );
break;
case IM_BANDFMT_UINT:
sign( unsigned int, signed char );
break;
case IM_BANDFMT_INT:
sign( signed int, signed char );
break;
case IM_BANDFMT_FLOAT:
sign( float, signed char );
break;
case IM_BANDFMT_DOUBLE:
sign( double, signed char );
break;
case IM_BANDFMT_COMPLEX:
sign_complex( float, float );
break;
case IM_BANDFMT_DPCOMPLEX:
sign_complex( double, double );
break;
default:
assert( 0 );
}
}
int
im_sign( IMAGE *in, IMAGE *out )
{
if( in->Coding != IM_CODING_NONE ) {
im_error( "im_sign", _( "not uncoded" ) );
return( -1 );
}
if( im_cp_desc( out, in ) )
return( -1 );
if( !im_iscomplex( in ) ) {
out->Bbits = IM_BBITS_BYTE;
out->BandFmt = IM_BANDFMT_CHAR;
}
/* Do the processing.
*/
if( im_wrapone( in, out, (im_wrapone_fn) buffer_sign, in, NULL ) )
return( -1 );
return( 0 );
}