83 lines
2.0 KiB
C
83 lines
2.0 KiB
C
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/* @(#) Gamma-correct uchar image with factor gammafactor.
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* @(#)
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* @(#) int im_gammacorrect(in, out, exponent)
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* @(#) IMAGE *in, *out;
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* @(#) double exponent;
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* @(#)
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* @(#) Returns 0 on sucess and -1 on error
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* @(#)
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*
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*
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* Copyright: 1990, N. Dessipris.
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*
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* Written on: 19/07/1990
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* Modified on:
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* 19/6/95 JC
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* - redone as library function
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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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 <vips/intl.h>
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#include <stdio.h>
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#include <vips/vips.h>
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#ifdef WITH_DMALLOC
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#include <dmalloc.h>
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#endif /*WITH_DMALLOC*/
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int
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im_gammacorrect( IMAGE *in, IMAGE *out, double exponent )
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{
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IMAGE *t1 = im_open_local( out, "im_gammacorrect:#1", "p" );
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IMAGE *t2 = im_open_local( out, "im_gammacorrect:#2", "p" );
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IMAGE *t3 = im_open_local( out, "im_gammacorrect:#2", "p" );
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if( !t1 || !t2 || !t3 )
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return( -1 );
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if( im_piocheck( in, out ) )
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return( -1 );
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if( in->BandFmt != IM_BANDFMT_UCHAR ) {
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im_errormsg( "im_gammacorrect: uchar images only" );
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return( -1 );
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}
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if( im_identity( t1, 1 ) ||
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im_powtra( t1, t2, exponent ) ||
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im_scale( t2, t3 ) ||
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im_maplut( in, out, t3 ) )
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return( -1 );
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return( 0 );
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}
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