/* 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;
}
