375 lines
8.9 KiB
C
375 lines
8.9 KiB
C
/* forward FFT
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*
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* Author: Nicos Dessipris
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* Written on: 12/04/1990
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* Modified on : 09/05/1990 to cope with float input
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* Modified on : 08/03/1991 history removed
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* Modified on : 03/04/1991 to cope with any input
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*
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* 28/6/95 JC
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* - rewritten to use im_clip2f() rather than own code
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* - memory leaks fixed
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* 10/9/98 JC
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* - frees memory more quickly
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* 2/4/02 JC
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* - fftw code added
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* 13/7/02 JC
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* - output Type set to IM_TYPE_FOURIER to help nip
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* 27/2/03 JC
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* - exploits real_to_complex() path in libfftw for real input (thanks
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* Matt) for a 2x speed-up
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* 17/11/03 JC
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* - fix a segv for wider than high images in the real_to_complex() path
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* (thanks Andrey)
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* - fixes to real_to_complex() path to give the correct result for
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* non-square images, including odd widths and heights
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* 3/11/04
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* - added fftw3 support
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* 7/2/10
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* - cleanups
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* - gtkdoc
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* 25/3/10
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* - have a "t" image linked to out to keep the image alive for longer
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* 27/1/12
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* - better setting of interpretation
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* - remove own fft fallback code
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* - remove fftw2 path
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* - reduce memuse
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* 3/1/14
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* - redone as a class
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*/
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/*
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This file is part of VIPS.
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VIPS is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA
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*/
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/*
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These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /*HAVE_CONFIG_H*/
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#include <glib/gi18n-lib.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <vips/vips.h>
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#include <vips/internal.h>
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#include "pfreqfilt.h"
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#ifdef HAVE_FFTW
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#include <fftw3.h>
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typedef struct _VipsFwfft {
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VipsFreqfilt parent_instance;
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} VipsFwfft;
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typedef VipsFreqfiltClass VipsFwfftClass;
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G_DEFINE_TYPE( VipsFwfft, vips_fwfft, VIPS_TYPE_FREQFILT );
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/* Real to complex forward transform.
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*/
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static int
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rfwfft1( VipsObject *object, VipsImage *in, VipsImage **out )
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{
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VipsFwfft *fwfft = (VipsFwfft *) object;
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VipsImage **t = (VipsImage **) vips_object_local_array( object, 4 );
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VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( fwfft );
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const guint64 size = VIPS_IMAGE_N_PELS( in );
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const int half_width = in->Xsize / 2 + 1;
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double *half_complex;
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double *planner_scratch;
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fftw_plan plan;
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double *buf, *q, *p;
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int x, y;
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if( vips_check_mono( class->nickname, in ) ||
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vips_check_uncoded( class->nickname, in ) )
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return( -1 );
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/* Convert input to a real double membuffer.
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*/
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t[1] = vips_image_new_memory();
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if( vips_cast_double( in, &t[0], NULL ) ||
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vips_image_write( t[0], t[1] ) )
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return( -1 );
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/* Make the plan for the transform. Yes, they really do use nx for
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* height and ny for width. Use a separate scratch buffer for the
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* planner, we can't overwrite real->data
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*/
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if( !(planner_scratch = VIPS_ARRAY( fwfft,
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VIPS_IMAGE_N_PELS( in ), double )) )
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return( -1 );
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if( !(half_complex = VIPS_ARRAY( fwfft,
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in->Ysize * half_width * 2, double )) )
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return( -1 );
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if( !(plan = fftw_plan_dft_r2c_2d( in->Ysize, in->Xsize,
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planner_scratch, (fftw_complex *) half_complex,
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0 )) ) {
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vips_error( class->nickname,
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"%s", _( "unable to create transform plan" ) );
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return( -1 );
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}
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fftw_execute_dft_r2c( plan,
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(double *) t[1]->data, (fftw_complex *) half_complex );
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fftw_destroy_plan( plan );
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/* Write to out as another memory buffer.
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*/
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*out = vips_image_new_memory();
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if( vips_image_pipelinev( *out, VIPS_DEMAND_STYLE_ANY, in, NULL ) )
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return( -1 );
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(*out)->BandFmt = VIPS_FORMAT_DPCOMPLEX;
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(*out)->Type = VIPS_INTERPRETATION_FOURIER;
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if( !(buf = VIPS_ARRAY( fwfft, VIPS_IMAGE_N_PELS( *out ), double )) )
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return( -1 );
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/* Copy and normalise. The right half is the up/down and
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* left/right flip of the left, but conjugated. Do the first
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* row separately, then mirror around the centre row.
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*/
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p = half_complex;
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q = buf;
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for( x = 0; x < half_width; x++ ) {
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q[0] = p[0] / size;
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q[1] = p[1] / size;
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p += 2;
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q += 2;
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}
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p = half_complex + ((in->Xsize + 1) / 2 - 1) * 2;
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for( x = half_width; x < (*out)->Xsize; x++ ) {
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q[0] = p[0] / size;
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q[1] = -1.0 * p[1] / size;
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p -= 2;
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q += 2;
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}
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if( vips_image_write_line( *out, 0, (VipsPel *) buf ) )
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return( -1 );
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for( y = 1; y < (*out)->Ysize; y++ ) {
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p = half_complex + y * half_width * 2;
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q = buf;
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for( x = 0; x < half_width; x++ ) {
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q[0] = p[0] / size;
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q[1] = p[1] / size;
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p += 2;
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q += 2;
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}
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/* Good grief.
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*/
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p = half_complex + 2 *
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(((*out)->Ysize - y + 1) * half_width - 2 +
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(in->Xsize & 1));
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for( x = half_width; x < (*out)->Xsize; x++ ) {
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q[0] = p[0] / size;
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q[1] = -1.0 * p[1] / size;
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p -= 2;
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q += 2;
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}
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if( vips_image_write_line( *out, y, (VipsPel *) buf ) )
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return( -1 );
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}
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return( 0 );
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}
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/* Complex to complex forward transform.
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*/
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static int
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cfwfft1( VipsObject *object, VipsImage *in, VipsImage **out )
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{
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VipsFwfft *fwfft = (VipsFwfft *) object;
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VipsImage **t = (VipsImage **) vips_object_local_array( object, 4 );
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VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( fwfft );
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fftw_plan plan;
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double *planner_scratch;
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double *buf, *q, *p;
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int x, y;
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if( vips_check_mono( class->nickname, in ) ||
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vips_check_uncoded( class->nickname, in ) )
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return( -1 );
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/* Convert input to a complex double membuffer.
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*/
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t[1] = vips_image_new_memory();
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if( vips_cast_dpcomplex( in, &t[0], NULL ) ||
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vips_image_write( t[0], t[1] ) )
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return( -1 );
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/* We have to have a separate buffer for the planner to work on.
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*/
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if( !(planner_scratch = VIPS_ARRAY( fwfft,
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VIPS_IMAGE_N_PELS( in ) * 2, double )) )
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return( -1 );
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/* Make the plan for the transform.
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*/
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if( !(plan = fftw_plan_dft_2d( in->Ysize, in->Xsize,
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(fftw_complex *) planner_scratch,
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(fftw_complex *) planner_scratch,
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FFTW_FORWARD,
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0 )) ) {
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vips_error( class->nickname,
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"%s", _( "unable to create transform plan" ) );
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return( -1 );
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}
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fftw_execute_dft( plan,
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(fftw_complex *) t[1]->data, (fftw_complex *) t[1]->data );
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fftw_destroy_plan( plan );
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/* Write to out as another memory buffer.
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*/
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*out = vips_image_new_memory();
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if( vips_image_pipelinev( *out, VIPS_DEMAND_STYLE_ANY, in, NULL ) )
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return( -1 );
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(*out)->BandFmt = VIPS_FORMAT_DPCOMPLEX;
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(*out)->Type = VIPS_INTERPRETATION_FOURIER;
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if( !(buf = VIPS_ARRAY( fwfft, VIPS_IMAGE_N_PELS( *out ), double )) )
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return( -1 );
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/* Copy to out, normalise.
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*/
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p = (double *) t[1]->data;
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for( y = 0; y < (*out)->Ysize; y++ ) {
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guint64 size = VIPS_IMAGE_N_PELS( *out );
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q = buf;
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for( x = 0; x < (*out)->Xsize; x++ ) {
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q[0] = p[0] / size;
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q[1] = p[1] / size;
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p += 2;
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q += 2;
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}
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if( vips_image_write_line( *out, y, (VipsPel *) buf ) )
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return( -1 );
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}
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return( 0 );
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}
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static int
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vips_fwfft_build( VipsObject *object )
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{
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VipsFreqfilt *freqfilt = VIPS_FREQFILT( object );
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VipsFwfft *fwfft = (VipsFwfft *) object;
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VipsImage **t = (VipsImage **) vips_object_local_array( object, 4 );
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VipsImage *in;
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if( VIPS_OBJECT_CLASS( vips_fwfft_parent_class )->
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build( object ) )
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return( -1 );
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in = freqfilt->in;
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if( vips_image_decode( in, &t[0] ) )
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return( -1 );
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in = t[0];
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if( vips_band_format_iscomplex( in->BandFmt ) ) {
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if( vips__fftproc( VIPS_OBJECT( fwfft ), in, &t[1],
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cfwfft1 ) )
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return( -1 );
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}
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else {
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if( vips__fftproc( VIPS_OBJECT( fwfft ), in, &t[1],
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rfwfft1 ) )
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return( -1 );
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}
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if( vips_image_write( t[1], freqfilt->out ) )
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return( -1 );
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return( 0 );
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}
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static void
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vips_fwfft_class_init( VipsFwfftClass *class )
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{
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VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
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vobject_class->nickname = "fwfft";
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vobject_class->description = _( "forward FFT" );
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vobject_class->build = vips_fwfft_build;
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}
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static void
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vips_fwfft_init( VipsFwfft *fwfft )
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{
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}
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#endif /*HAVE_FFTW*/
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/**
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* vips_fwfft: (method)
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* @in: input image
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* @out: (out): output image
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* @...: %NULL-terminated list of optional named arguments
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*
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* Transform an image to Fourier space.
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*
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* VIPS uses the fftw Fourier Transform library. If this library was not
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* available when VIPS was configured, these functions will fail.
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*
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* See also: vips_invfft().
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*
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* Returns: 0 on success, -1 on error.
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*/
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int
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vips_fwfft( VipsImage *in, VipsImage **out, ... )
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{
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va_list ap;
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int result;
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va_start( ap, out );
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result = vips_call_split( "fwfft", ap, in, out );
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va_end( ap );
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return( result );
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}
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