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/* im_addgnoise
*
* Copyright 1990, N. Dessipris.
*
* File written on 2/12/1986
* Author : N. Dessipris
* Updated : 22/01/1991
* 1/2/95 JC
* - junked!
* - now uses partial im_gaussnoise() and partial im_add() to do the
* same job
& 1/5/01 JC
* - oops, failed for not-1-band images
*
* 2008-01-28 tcv:
* - now works (was broken)
* - no limit on bands
* 4/2/10
* - no need to bandup here now, im_add() does that
* - gtkdoc
*/
/*
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 <vips/vips.h>
/**
* im_addgnoise:
* @in: input image
* @out: output image
* @sigma: standard deviation of noise
*
* Add gaussian noise with mean 0 and variance sigma to @in.
* The noise is generated by averaging 12 random numbers,
* see page 78, PIETGEN, 1989.
*
* See also: im_gaussnoise().
*
* Returns: 0 on success, -1 on error
*/
int
im_addgnoise( IMAGE *in, IMAGE *out, double sigma )
{
IMAGE *t;
if( !(t = im_open_local( out, "im_addgnoise", "p" )) ||
im_gaussnoise( t, in->Xsize, in->Ysize, 0, sigma ) ||
im_add( in, t, out ) )
return( -1 );
return( 0 );
}
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