158 lines
3.5 KiB
C
158 lines
3.5 KiB
C
/* @(#) Creates a Gaussian noisy float image with mean of 0 and variance of 1
|
|
* @(#) by averaging 12 random numbers
|
|
* @(#) Creates one band float image
|
|
* @(#) page 78 PIETGEN 1989 n = 12
|
|
* @(#) Usage
|
|
* @(#)
|
|
* @(#) int im_gaussnoise(image, xsize, ysize, mean, sigma)
|
|
* @(#) IMAGE *image;
|
|
* @(#) int xsize, ysize;
|
|
* @(#) double mean, sigma;
|
|
* @(#)
|
|
* @(#) Returns 0 on success and -1 on error
|
|
*
|
|
* Copyright 1990, N. Dessipris.
|
|
*
|
|
* File written on 2/12/1986
|
|
* Author : N. Dessipris
|
|
* Updated : 6/6/1991
|
|
* 21/7/93 JC
|
|
* - im_outcheck() call added
|
|
* 1/2/95 JC
|
|
* - declaration for drand48() added
|
|
* - partialised, adapting im_black()
|
|
* 23/10/98 JC
|
|
* - drand48() chaged to random() for poartability
|
|
* 21/10/02 JC
|
|
* - tries rand() if random() is not available
|
|
* - uses RAND_MAX, d'oh
|
|
*/
|
|
|
|
/*
|
|
|
|
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 <stdlib.h>
|
|
|
|
#include <vips/vips.h>
|
|
|
|
#ifdef WITH_DMALLOC
|
|
#include <dmalloc.h>
|
|
#endif /*WITH_DMALLOC*/
|
|
|
|
/* Keep parameters here.
|
|
*/
|
|
typedef struct {
|
|
double mean;
|
|
double sigma;
|
|
} GnoiseInfo;
|
|
|
|
/* Generate function --- just fill the region with noise. "dummy" is our
|
|
* sequence value: we don't need one.
|
|
*/
|
|
/*ARGSUSED*/
|
|
static int
|
|
gnoise_gen( REGION *or, void *dummy, GnoiseInfo *gin )
|
|
{
|
|
int x, y, i;
|
|
int sz = IM_REGION_N_ELEMENTS( or );
|
|
|
|
for( y = 0; y < or->valid.height; y++ ) {
|
|
float *q = (float *)
|
|
IM_REGION_ADDR( or, or->valid.left, y + or->valid.top );
|
|
|
|
for( x = 0; x < sz; x++ ) {
|
|
double sum = 0.0;
|
|
|
|
for( i = 0; i < 12; i++ )
|
|
#ifdef HAVE_RANDOM
|
|
sum += (double) random() / RAND_MAX;
|
|
#else /*HAVE_RANDOM*/
|
|
#ifdef HAVE_RAND
|
|
sum += (double) rand() / RAND_MAX;
|
|
#else /*HAVE_RAND*/
|
|
#error "no random number generator found"
|
|
#endif /*HAVE_RAND*/
|
|
#endif /*HAVE_RAND*/
|
|
|
|
q[x] = (sum - 6.0) * gin->sigma + gin->mean;
|
|
}
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* Make a one band float image of gaussian noise.
|
|
*/
|
|
int
|
|
im_gaussnoise( IMAGE *out, int x, int y, double mean, double sigma )
|
|
{
|
|
GnoiseInfo *gin;
|
|
|
|
/* Check parameters.
|
|
*/
|
|
if( x < 0 || y < 0 ) {
|
|
im_errormsg( "im_gaussnoise: bad parameter" );
|
|
return( -1 );
|
|
}
|
|
|
|
/* Check descriptor.
|
|
*/
|
|
if( im_poutcheck( out ) )
|
|
return( -1 );
|
|
|
|
/* Set fields.
|
|
*/
|
|
im_initdesc( out,
|
|
x, y, 1,
|
|
IM_BBITS_FLOAT, IM_BANDFMT_FLOAT, IM_CODING_NONE, IM_TYPE_B_W,
|
|
1.0, 1.0, 0, 0 );
|
|
|
|
/* Set hints - ANY is ok with us.
|
|
*/
|
|
if( im_demand_hint( out, IM_ANY, NULL ) )
|
|
return( -1 );
|
|
|
|
/* Save parameters.
|
|
*/
|
|
if( !(gin = IM_NEW( out, GnoiseInfo )) )
|
|
return( -1 );
|
|
gin->mean = mean;
|
|
gin->sigma = sigma;
|
|
|
|
/* Generate image.
|
|
*/
|
|
if( im_generate( out, NULL, gnoise_gen, NULL, gin, NULL ) )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|