139 lines
3.2 KiB
C
139 lines
3.2 KiB
C
/* make a displayable power spectrum for an image
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*
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* Author: Nicos Dessipris
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* Written on: 27/03/1991
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* Modified on :
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* 16/6/93 J.Cupitt
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* - im_ioflag() changed to im_iocheck()
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* 23/2/95 JC
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* - rewritten for partials
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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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* - any number of bands
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* 7/2/10
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* - gtkdoc
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* - cleanups
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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 "pfreqfilt.h"
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typedef VipsFreqfilt VipsSpectrum;
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typedef VipsFreqfiltClass VipsSpectrumClass;
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G_DEFINE_TYPE( VipsSpectrum, vips_spectrum, VIPS_TYPE_FREQFILT );
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static int
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vips_spectrum_build( VipsObject *object )
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{
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VipsFreqfilt *freqfilt = VIPS_FREQFILT( object );
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VipsImage **t = (VipsImage **) vips_object_local_array( object, 5 );
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VipsImage *in;
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if( VIPS_OBJECT_CLASS( vips_spectrum_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( in->BandFmt != VIPS_FORMAT_COMPLEX ) {
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if( vips_fwfft( in, &t[0], NULL ) )
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return( -1 );
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in = t[0];
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}
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if( vips_abs( in, &t[1], NULL ) ||
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vips_scale( t[1], &t[2], "log", TRUE, NULL ) ||
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vips_wrap( t[2], &t[3], NULL ) )
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return( -1 );
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if( vips_image_write( t[3], 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_spectrum_class_init( VipsSpectrumClass *class )
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{
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VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
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vobject_class->nickname = "spectrum";
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vobject_class->description = _( "make displayable power spectrum" );
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vobject_class->build = vips_spectrum_build;
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}
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static void
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vips_spectrum_init( VipsSpectrum *spectrum )
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{
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}
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/**
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* vips_spectrum: (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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* Make a displayable (ie. 8-bit unsigned int) power spectrum.
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*
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* If @in is non-complex, it is transformed to Fourier space. Then the
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* absolute value is passed through vips_scale() in log mode, and vips_wrap().
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*
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* See also: vips_fwfft(), vips_scale(), vips_wrap().
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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_spectrum( 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( "spectrum", ap, in, out );
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va_end( ap );
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return( result );
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}
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