libvips/libvips/freq_filt/im_fwfft.c

379 lines
8.8 KiB
C

/* im_fwfft
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 12/04/1990
* Modified on : 09/05/1990 to cope with float input
* Modified on : 08/03/1991 history removed
* Modified on : 03/04/1991 to cope with any input
*
* 28/6/95 JC
* - rewritten to use im_clip2f() rather than own code
* - memory leaks fixed
* 10/9/98 JC
* - frees memory more quickly
* 2/4/02 JC
* - fftw code added
* 13/7/02 JC
* - output Type set to IM_TYPE_FOURIER to help nip
* 27/2/03 JC
* - exploits real_to_complex() path in libfftw for real input (thanks
* Matt) for a 2x speed-up
* 17/11/03 JC
* - fix a segv for wider than high images in the real_to_complex() path
* (thanks Andrey)
* - fixes to real_to_complex() path to give the correct result for
* non-square images, including odd widths and heights
* 3/11/04
* - added fftw3 support
* 7/2/10
* - cleanups
* - gtkdoc
* 25/3/10
* - have a "t" image linked to out to keep the image alive for longer
* 27/1/12
* - better setting of interpretation
* - remove own fft fallback code
*/
/*
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 <math.h>
#ifdef HAVE_FFTW
#include <fftw3.h>
#endif /*HAVE_FFTW*/
#include <vips/vips.h>
#include <vips/internal.h>
#ifdef HAVE_FFTW
/* Real to complex forward transform.
*/
static int
rfwfft1( IMAGE *dummy, IMAGE *in, IMAGE *out )
{
const guint64 size = VIPS_IMAGE_N_PELS( in );
const int half_width = in->Xsize / 2 + 1;
IMAGE *real;
double *half_complex;
double *planner_scratch;
fftw_plan plan;
double *buf, *q, *p;
int x, y;
if( vips_check_mono( "im_fwfft", in ) ||
vips_check_uncoded( "im_fwfft", in ) )
return( -1 );
/* Convert input to a real double membuffer.
*/
if( !(real = im_open_local( dummy, "fwfft1:1", "t" )) ||
im_clip2fmt( in, real, IM_BANDFMT_DOUBLE ) )
return( -1 );
/* Make the plan for the transform. Yes, they really do use nx for
* height and ny for width. Use a separate scratch buffer for the
* planner, we can't overwrite real->data
*/
if( !(planner_scratch = IM_ARRAY( dummy,
VIPS_IMAGE_N_PELS( in ), double )) )
return( -1 );
if( !(half_complex = IM_ARRAY( dummy,
in->Ysize * half_width * 2, double )) )
return( -1 );
if( !(plan = fftw_plan_dft_r2c_2d( in->Ysize, in->Xsize,
planner_scratch, (fftw_complex *) half_complex,
0 )) ) {
im_error( "im_fwfft",
"%s", _( "unable to create transform plan" ) );
return( -1 );
}
if( im_incheck( real ) )
return( -1 );
fftw_execute_dft_r2c( plan,
(double *) real->data, (fftw_complex *) half_complex );
fftw_destroy_plan( plan );
/* WIO to out.
*/
if( im_cp_desc( out, in ) )
return( -1 );
out->BandFmt = IM_BANDFMT_DPCOMPLEX;
out->Type = IM_TYPE_FOURIER;
if( im_setupout( out ) )
return( -1 );
if( !(buf = (double *) IM_ARRAY( dummy,
IM_IMAGE_SIZEOF_LINE( out ), VipsPel )) )
return( -1 );
/* Copy to out and normalise. The right half is the up/down and
* left/right flip of the left, but conjugated. Do the first
* row separately, then mirror around the centre row.
*/
p = half_complex;
q = buf;
for( x = 0; x < half_width; x++ ) {
q[0] = p[0] / size;
q[1] = p[1] / size;
p += 2;
q += 2;
}
p = half_complex + ((in->Xsize + 1) / 2 - 1) * 2;
for( x = half_width; x < out->Xsize; x++ ) {
q[0] = p[0] / size;
q[1] = -1.0 * p[1] / size;
p -= 2;
q += 2;
}
if( im_writeline( 0, out, (VipsPel *) buf ) )
return( -1 );
for( y = 1; y < out->Ysize; y++ ) {
p = half_complex + y * half_width * 2;
q = buf;
for( x = 0; x < half_width; x++ ) {
q[0] = p[0] / size;
q[1] = p[1] / size;
p += 2;
q += 2;
}
/* Good grief.
*/
p = half_complex + 2 *
((out->Ysize - y + 1) * half_width - 2 +
(in->Xsize & 1));
for( x = half_width; x < out->Xsize; x++ ) {
q[0] = p[0] / size;
q[1] = -1.0 * p[1] / size;
p -= 2;
q += 2;
}
if( im_writeline( y, out, (VipsPel *) buf ) )
return( -1 );
}
return( 0 );
}
/* Complex to complex forward transform.
*/
static int
cfwfft1( IMAGE *dummy, IMAGE *in, IMAGE *out )
{
IMAGE *cmplx;
fftw_plan plan;
double *planner_scratch;
double *buf, *q, *p;
int x, y;
if( vips_check_mono( "im_fwfft", in ) ||
vips_check_uncoded( "im_fwfft", in ) )
return( -1 );
if( !(cmplx = im_open_local( dummy, "fwfft1:1", "t" )) ||
im_pincheck( in ) ||
im_outcheck( out ) )
return( -1 );
if( im_clip2fmt( in, cmplx, IM_BANDFMT_DPCOMPLEX ) )
return( -1 );
/* We have to have a separate buffer for the planner to work on.
*/
if( !(planner_scratch = IM_ARRAY( dummy,
VIPS_IMAGE_N_PELS( in ) * 2, double )) )
return( -1 );
/* Make the plan for the transform.
*/
if( !(plan = fftw_plan_dft_2d( in->Ysize, in->Xsize,
(fftw_complex *) planner_scratch,
(fftw_complex *) planner_scratch,
FFTW_FORWARD,
0 )) ) {
im_error( "im_fwfft",
"%s", _( "unable to create transform plan" ) );
return( -1 );
}
fftw_execute_dft( plan,
(fftw_complex *) cmplx->data, (fftw_complex *) cmplx->data );
fftw_destroy_plan( plan );
/* WIO to out.
*/
if( im_cp_desc( out, in ) )
return( -1 );
out->BandFmt = IM_BANDFMT_DPCOMPLEX;
out->Type = IM_TYPE_FOURIER;
if( im_setupout( out ) )
return( -1 );
if( !(buf = (double *) IM_ARRAY( dummy,
IM_IMAGE_SIZEOF_LINE( out ), VipsPel )) )
return( -1 );
/* Copy to out, normalise.
*/
for( p = (double *) cmplx->data, y = 0; y < out->Ysize; y++ ) {
guint64 size = VIPS_IMAGE_N_PELS( out );
q = buf;
for( x = 0; x < out->Xsize; x++ ) {
q[0] = p[0] / size;
q[1] = p[1] / size;
p += 2;
q += 2;
}
if( im_writeline( y, out, (VipsPel *) buf ) )
return( -1 );
}
return( 0 );
}
static int
fwfft1( IMAGE *dummy, IMAGE *in, IMAGE *out )
{
if( vips_bandfmt_iscomplex( in->BandFmt ) )
return( cfwfft1( dummy, in, out ) );
else
return( rfwfft1( dummy, in, out ) );
}
#else
static int
fwfft1( IMAGE *dummy, IMAGE *in, IMAGE *out )
{
im_error( "im_fwfft",
"%s", _( "vips configured without FFT support" ) );
return( -1 );
}
#endif
/* Transform an n-band image with a 1-band processing function.
*
* Memory strategy: we need memory buffers for the input and the output of
* fftw. In some modes fftw generates only half the output and we construct
* the rest.
*
* input pipeline ->
* bandsplit ->
* full memory image, freed when im_*fft*() exits ->
* fftw ->
* half memory image, freed when im_*fft*() exits ->
* full memory image, freed when @out is freed ->
* partial bandjoin ->
* output pipeline
*
* im__fftproc() needs to just call im__fftproc_fn directly for 1 band images,
* so we can't cache the output in this fn.
*/
int
im__fftproc( IMAGE *dummy, IMAGE *in, IMAGE *out, im__fftproc_fn fn )
{
IMAGE **bands;
IMAGE **fft;
int b;
if( in->Bands == 1 )
return( fn( dummy, in, out ) );
if( !(bands = IM_ARRAY( dummy, in->Bands, IMAGE * )) ||
im_open_local_array( dummy, bands, in->Bands, "bands", "p" ) )
return( -1 );
if( !(fft = IM_ARRAY( out, in->Bands, IMAGE * )) ||
im_open_local_array( out, fft, in->Bands, "fft", "p" ) )
return( -1 );
for( b = 0; b < in->Bands; b++ )
if( im_extract_band( in, bands[b], b ) ||
fn( dummy, bands[b], fft[b] ) )
return( -1 );
if( im_gbandjoin( fft, out, in->Bands ) )
return( -1 );
return( 0 );
}
/**
* im_fwfft:
* @in: input image
* @out: output image
*
* Transform an image to Fourier space.
*
* VIPS uses the fftw Fourier Transform library. If this library was not
* available when VIPS was configured, these functions will fail.
*
* See also: im_invfft(), im_disp_ps().
*
* Returns: 0 on success, -1 on error.
*/
int
im_fwfft( IMAGE *in, IMAGE *out )
{
IMAGE *dummy;
if( !(dummy = im_open( "im_fwfft:1", "p" )) )
return( -1 );
if( im__fftproc( dummy, in, out, fwfft1 ) ) {
im_close( dummy );
return( -1 );
}
im_close( dummy );
return( 0 );
}