libvips/libvips/freqfilt/phasecor.c

151 lines
3.5 KiB
C

/* Like spcor, but calculates phase correlation in the Fourier domain.
*
* Copyright: 2008, Nottingham Trent University
*
* Author: Tom Vajzovic
* Written on: 2008-01-16
* 7/2/10
* - cleanups
* - gtkdoc
* 3/1/14
* - redone as a class
*/
/*
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., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 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 <glib/gi18n-lib.h>
#include <stdio.h>
#include <stdlib.h>
#include <vips/vips.h>
#include "pfreqfilt.h"
typedef struct _VipsPhasecor {
VipsFreqfilt parent_instance;
VipsImage *in2;
} VipsPhasecor;
typedef VipsFreqfiltClass VipsPhasecorClass;
G_DEFINE_TYPE( VipsPhasecor, vips_phasecor, VIPS_TYPE_FREQFILT );
static int
vips_phasecor_build( VipsObject *object )
{
VipsFreqfilt *freqfilt = VIPS_FREQFILT( object );
VipsPhasecor *phasecor = (VipsPhasecor *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 5 );
VipsImage *in1, *in2;
if( VIPS_OBJECT_CLASS( vips_phasecor_parent_class )->
build( object ) )
return( -1 );
in1 = freqfilt->in;
in2 = phasecor->in2;
if( in1->BandFmt != VIPS_FORMAT_COMPLEX ) {
if( vips_fwfft( in1, &t[0], NULL ) )
return( -1 );
in1 = t[0];
}
if( in2->BandFmt != VIPS_FORMAT_COMPLEX ) {
if( vips_fwfft( in2, &t[1], NULL ) )
return( -1 );
in2 = t[1];
}
if( vips_cross_phase( in1, in2, &t[2], NULL ) ||
vips_invfft( t[2], &t[3], "real", TRUE, NULL ) ||
vips_image_write( t[3], freqfilt->out ) )
return( -1 );
return( 0 );
}
static void
vips_phasecor_class_init( VipsPhasecorClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
vobject_class->nickname = "phasecor";
vobject_class->description = _( "calculate phase correlation" );
vobject_class->build = vips_phasecor_build;
VIPS_ARG_IMAGE( class, "in2", 0,
_( "in2" ),
_( "Second input image" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsPhasecor, in2 ) );
}
static void
vips_phasecor_init( VipsPhasecor *phasecor )
{
}
/**
* vips_phasecor:
* @in1: first input image
* @in2: second input image
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Convert the two input images to Fourier space, calculate phase-correlation,
* back to real space.
*
* See also: vips_fwfft(), vips_cross_phase(),
*
* Returns: 0 on success, -1 on error.
*/
int
vips_phasecor( VipsImage *in1, VipsImage *in2, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "phasecor", ap, in1, in2, out );
va_end( ap );
return( result );
}