1 /* avg ... average value of image
2 *
3 * Copyright: 1990, J. Cupitt
4 *
5 * Author: J. Cupitt
6 * Written on: 02/08/1990
7 * Modified on:
8 * 5/5/93 JC
9 * - now does partial images
10 * - less likely to overflow
11 * 1/7/93 JC
12 * - adapted for partial v2
13 * - ANSI C
14 * 21/2/95 JC
15 * - modernised again
16 * 11/5/95 JC
17 * - oops! return( NULL ) in im_avg(), instead of return( -1 )
18 * 20/6/95 JC
19 * - now returns double
20 * 13/1/05
21 * - use 64 bit arithmetic
22 * 8/12/06
23 * - add liboil support
24 * 18/8/09
25 * - gtkdoc, minor reformatting
26 * 7/9/09
27 * - rewrite for im__wrapiter()
28 * - add complex case (needed for im_max())
29 * 8/9/09
30 * - wrapscan stuff moved here
31 * 31/7/10
32 * - remove liboil
33 * 24/8/11
34 * - rewrite as a class
35 * 12/9/14
36 * - oops, fix complex avg
37 */
38
39 /*
40
41 This file is part of VIPS.
42
43 VIPS is free software; you can redistribute it and/or modify
44 it under the terms of the GNU Lesser General Public License as published by
45 the Free Software Foundation; either version 2 of the License, or
46 (at your option) any later version.
47
48 This program is distributed in the hope that it will be useful,
49 but WITHOUT ANY WARRANTY; without even the implied warranty of
50 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
51 GNU Lesser General Public License for more details.
52
53 You should have received a copy of the GNU Lesser General Public License
54 along with this program; if not, write to the Free Software
55 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
56 02110-1301 USA
57
58 */
59
60 /*
61
62 These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
63
64 */
65
66 #ifdef HAVE_CONFIG_H
67 #include <config.h>
68 #endif /*HAVE_CONFIG_H*/
69 #include <vips/intl.h>
70
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <math.h>
74
75 #include <vips/vips.h>
76 #include <vips/internal.h>
77
78 #include "statistic.h"
79
80 typedef struct _VipsAvg {
81 VipsStatistic parent_instance;
82
83 double sum;
84 double out;
85 } VipsAvg;
86
87 typedef VipsStatisticClass VipsAvgClass;
88
89 G_DEFINE_TYPE( VipsAvg, vips_avg, VIPS_TYPE_STATISTIC );
90
91 static int
vips_avg_build(VipsObject * object)92 vips_avg_build( VipsObject *object )
93 {
94 VipsStatistic *statistic = VIPS_STATISTIC( object );
95 VipsAvg *avg = (VipsAvg *) object;
96
97 gint64 vals;
98 double average;
99
100 if( VIPS_OBJECT_CLASS( vips_avg_parent_class )->build( object ) )
101 return( -1 );
102
103 vals = (gint64)
104 vips_image_get_width( statistic->in ) *
105 vips_image_get_height( statistic->in ) *
106 vips_image_get_bands( statistic->in );
107 average = avg->sum / vals;
108 g_object_set( object, "out", average, NULL );
109
110 return( 0 );
111 }
112
113 /* Start function: allocate space for a double in which we can accumulate the
114 * sum for this thread.
115 */
116 static void *
vips_avg_start(VipsStatistic * statistic)117 vips_avg_start( VipsStatistic *statistic )
118 {
119 return( (void *) g_new0( double, 1 ) );
120 }
121
122 /* Stop function. Add this little sum to the main sum.
123 */
124 static int
vips_avg_stop(VipsStatistic * statistic,void * seq)125 vips_avg_stop( VipsStatistic *statistic, void *seq )
126 {
127 VipsAvg *avg = (VipsAvg *) statistic;
128 double *sum = (double *) seq;
129
130 avg->sum += *sum;
131
132 g_free( seq );
133
134 return( 0 );
135 }
136
137 /* Sum pels in this section.
138 */
139 #define LOOP( TYPE ) { \
140 TYPE *p = (TYPE *) in; \
141 \
142 for( i = 0; i < sz; i++ ) \
143 m += p[i]; \
144 }
145
146 #define CLOOP( TYPE ) { \
147 TYPE *p = (TYPE *) in; \
148 \
149 for( i = 0; i < sz; i++ ) { \
150 double mod = sqrt( p[0] * p[0] + p[1] * p[1] ); \
151 \
152 m += mod; \
153 p += 2; \
154 } \
155 }
156
157 /* Loop over region, accumulating a sum in *tmp.
158 */
159 static int
vips_avg_scan(VipsStatistic * statistic,void * seq,int x,int y,void * in,int n)160 vips_avg_scan( VipsStatistic *statistic, void *seq,
161 int x, int y, void *in, int n )
162 {
163 const int sz = n * vips_image_get_bands( statistic->in );
164
165 double *sum = (double *) seq;
166
167 int i;
168 double m;
169
170 m = *sum;
171
172 /* Now generate code for all types.
173 */
174 switch( vips_image_get_format( statistic->in ) ) {
175 case VIPS_FORMAT_UCHAR: LOOP( unsigned char ); break;
176 case VIPS_FORMAT_CHAR: LOOP( signed char ); break;
177 case VIPS_FORMAT_USHORT: LOOP( unsigned short ); break;
178 case VIPS_FORMAT_SHORT: LOOP( signed short ); break;
179 case VIPS_FORMAT_UINT: LOOP( unsigned int ); break;
180 case VIPS_FORMAT_INT: LOOP( signed int ); break;
181 case VIPS_FORMAT_FLOAT: LOOP( float ); break;
182 case VIPS_FORMAT_DOUBLE: LOOP( double ); break;
183 case VIPS_FORMAT_COMPLEX: CLOOP( float ); break;
184 case VIPS_FORMAT_DPCOMPLEX: CLOOP( double ); break;
185
186 default:
187 g_assert_not_reached();
188 }
189
190 *sum = m;
191
192 return( 0 );
193 }
194
195 static void
vips_avg_class_init(VipsAvgClass * class)196 vips_avg_class_init( VipsAvgClass *class )
197 {
198 GObjectClass *gobject_class = (GObjectClass *) class;
199 VipsObjectClass *object_class = (VipsObjectClass *) class;
200 VipsStatisticClass *sclass = VIPS_STATISTIC_CLASS( class );
201
202 gobject_class->set_property = vips_object_set_property;
203 gobject_class->get_property = vips_object_get_property;
204
205 object_class->nickname = "avg";
206 object_class->description = _( "find image average" );
207 object_class->build = vips_avg_build;
208
209 sclass->start = vips_avg_start;
210 sclass->scan = vips_avg_scan;
211 sclass->stop = vips_avg_stop;
212
213 VIPS_ARG_DOUBLE( class, "out", 2,
214 _( "Output" ),
215 _( "Output value" ),
216 VIPS_ARGUMENT_REQUIRED_OUTPUT,
217 G_STRUCT_OFFSET( VipsAvg, out ),
218 -INFINITY, INFINITY, 0.0 );
219 }
220
221 static void
vips_avg_init(VipsAvg * avg)222 vips_avg_init( VipsAvg *avg )
223 {
224 }
225
226
227 /**
228 * vips_avg: (method)
229 * @in: input #VipsImage
230 * @out: (out): output pixel average
231 * @...: %NULL-terminated list of optional named arguments
232 *
233 * This operation finds the average value in an image. It operates on all
234 * bands of the input image: use vips_stats() if you need to calculate an
235 * average for each band. For complex images, return the average modulus.
236 *
237 * See also: vips_stats(), vips_bandmean(), vips_deviate(), vips_rank()
238 *
239 * Returns: 0 on success, -1 on error
240 */
241 int
vips_avg(VipsImage * in,double * out,...)242 vips_avg( VipsImage *in, double *out, ... )
243 {
244 va_list ap;
245 int result;
246
247 va_start( ap, out );
248 result = vips_call_split( "avg", ap, in, out );
249 va_end( ap );
250
251 return( result );
252 }
253