| /* im_gaussnoise |
| * |
| * 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 portability |
| * 21/10/02 JC |
| * - tries rand() if random() is not available |
| * - uses RAND_MAX, d'oh |
| * 29/1/10 |
| * - cleanups |
| * - 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 <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 *seq, void *a, void *b ) |
| { |
| GnoiseInfo *gin = (GnoiseInfo *) a; |
| 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 ); |
| } |
| |
| /** |
| * im_gaussnoise: |
| * @out: output image |
| * @x: output width |
| * @y: output height |
| * @mean: average value in output |
| * @sigma: standard deviation in output |
| * |
| * Make a one band float image of gaussian noise with the specified |
| * distribution. The noise distribution is created by averaging 12 random |
| * numbers with the appropriate weights. |
| * |
| * See also: im_addgnoise(), im_make_xy(), im_text(), im_black(). |
| * |
| * Returns: 0 on success, -1 on error |
| */ |
| int |
| im_gaussnoise( IMAGE *out, int x, int y, double mean, double sigma ) |
| { |
| GnoiseInfo *gin; |
| |
| if( x <= 0 || y <= 0 ) { |
| im_error( "im_gaussnoise", "%s", _( "bad parameter" ) ); |
| return( -1 ); |
| } |
| |
| if( im_poutcheck( out ) ) |
| return( -1 ); |
| 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 ); |
| 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; |
| |
| if( im_generate( out, NULL, gnoise_gen, NULL, gin, NULL ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |