libvips/libvips/freqfilt/freqmult.c

173 lines
4.3 KiB
C

/* frequency-domain filter an image
*
* Author: Nicos Dessipris
* Written on: 02/05/1990
* Modified on : 08/03/1991
* 16/6/93 J.Cupitt
* - im_multiply() called, rather than im_cmultim()
* 27/10/93 JC
* - im_clip2*() called, rather than im_any2*()
* 20/9/95 JC
* - rewritten
* 10/9/98 JC
* - frees memory more quickly
* 4/3/03 JC
* - use im_invfftr() to get real back for speedup
* 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 _VipsFreqmult {
VipsFreqfilt parent_instance;
VipsImage *mask;
} VipsFreqmult;
typedef VipsFreqfiltClass VipsFreqmultClass;
G_DEFINE_TYPE( VipsFreqmult, vips_freqmult, VIPS_TYPE_FREQFILT );
static int
vips_freqmult_build( VipsObject *object )
{
VipsFreqfilt *freqfilt = VIPS_FREQFILT( object );
VipsFreqmult *freqmult = (VipsFreqmult *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 5 );
VipsImage *in;
if( VIPS_OBJECT_CLASS( vips_freqmult_parent_class )->
build( object ) )
return( -1 );
in = freqfilt->in;
if( vips_band_format_iscomplex( in->BandFmt ) ) {
if( vips_multiply( in, freqmult->mask, &t[0], NULL ) ||
vips_invfft( t[0], &t[1], "real", TRUE, NULL ) )
return( -1 );
in = t[1];
}
else {
/* Optimisation: output of vips_invfft() is double, we
* will usually cast to char, so rather than keeping a
* large double buffer and partial to char from that,
* cast to a memory buffer and copy to out from that.
*
* FIXME does this actually work now we're a class? test
* perhaps we need a temporary object
*/
t[4] = vips_image_new_memory();
if( vips_fwfft( in, &t[0], NULL ) ||
vips_multiply( t[0], freqmult->mask, &t[1], NULL ) ||
vips_invfft( t[1], &t[2], "real", TRUE, NULL ) ||
vips_cast( t[2], &t[3], in->BandFmt, NULL ) ||
vips_image_write( t[3], t[4] ) )
return( -1 );
in = t[4];
}
if( vips_image_write( in, freqfilt->out ) )
return( -1 );
return( 0 );
}
static void
vips_freqmult_class_init( VipsFreqmultClass *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 = "freqmult";
vobject_class->description = _( "frequency-domain filtering" );
vobject_class->build = vips_freqmult_build;
VIPS_ARG_IMAGE( class, "mask", 0,
_( "Mask" ),
_( "Input mask image" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsFreqmult, mask ) );
}
static void
vips_freqmult_init( VipsFreqmult *freqmult )
{
}
/**
* vips_freqmult: (method)
* @in: input image
* @mask: mask image
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Multiply @in by @mask in Fourier space.
*
* @in is transformed to Fourier space, multipled with @mask, then
* transformed back to real space. If @in is already a complex image, just
* multiply then inverse transform.
*
* See also: vips_invfft(), vips_mask_ideal().
*
* Returns: 0 on success, -1 on error.
*/
int
vips_freqmult( VipsImage *in, VipsImage *mask, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "freqmult", ap, in, mask, out );
va_end( ap );
return( result );
}