91 lines
2.5 KiB
C
91 lines
2.5 KiB
C
/* @(#) Add gaussian noise with mean 0 and variance sigma to image
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* @(#) The noise is generated by averaging 12 random numbers
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* @(#) page 78 PIETGEN 1989 n = 12
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* @(#) Input image is any, output is float
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* @(#) If running on SYSTEM V CONSTANT should be replaced by 2**15 - 1
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* @(#) Usage
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* @(#)
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* @(#) int im_addgnoise(imin, imout, sigma)
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* @(#) IMAGE *imin, *imout;
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* @(#) double sigma;
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* @(#) Returns 0 on success and -1 on error
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* @(#)
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*
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* Copyright 1990, N. Dessipris.
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*
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* File written on 2/12/1986
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* Author : N. Dessipris
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* Updated : 22/01/1991
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* 1/2/95 JC
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* - junked!
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* - now uses partial im_gaussnoise() and partial im_add() to do the
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* same job
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& 1/5/01 JC
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* - oops, failed for not-1-band images
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*
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* 2008-01-28 tcv:
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* - now works (was broken)
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* - no limit on bands
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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 <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_addgnoise( IMAGE *in, IMAGE *out, double sigma ){
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#define FUNCTION_NAME "im_addgnoise"
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if( im_piocheck( in, out ))
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return -1;
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{
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int i;
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IMAGE **temps= IM_ARRAY( out, in-> Bands, IMAGE* );
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IMAGE *joined_temps= im_open_local( out, FUNCTION_NAME ": joined_temps", "p" );
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if( ! temps || ! joined_temps || im_open_local_array( out, temps, in-> Bands, FUNCTION_NAME ": temps", "p" ))
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return -1;
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for( i= 0; i < in-> Bands; ++i )
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if( im_gaussnoise( temps[i], in-> Xsize, in-> Ysize, 0.0, sigma ))
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return -1;
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return im_gbandjoin( temps, joined_temps, in-> Bands ) || im_add( in, joined_temps, out );
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}
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#undef FUNCTION_NAME
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}
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