add stats.c

This commit is contained in:
John Cupitt 2011-11-07 14:53:18 +00:00
parent cb753e16fa
commit 844ee2c13f
2 changed files with 256 additions and 2 deletions

View File

@ -137,8 +137,8 @@ im__wrapscan( VipsImage *in,
}
/* Get the value of pixel (0, 0). Use this to init the min/max value for
* * im_max()/im_stats()/etc.
* */
* im_max()/im_stats()/etc.
*/
int
im__value( IMAGE *im, double *value )
{

254
libvips/arithmetic/stats.c Normal file
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@ -0,0 +1,254 @@
/* stats.c ... many image stats in a single pass
*
(C) Kirk Martinez 1993
23/4/93 J.Cupitt
- adapted to partial images
- special struct abandoned; now returns DOUBLEMASK.
1/7/93 JC
- adapted for partial v2
- ANSIfied
27/7/93 JC
- init of mask changed to use actual values, not IM_MAXDOUBLE and
(-IM_MAXDOUBLE). These caused problems when assigned to floats.
funny business with offset==42, yuk!
31/8/93 JC
- forgot to init global max/min properly! sorry.
21/6/95 JC
- still did not init max and min correctly --- now fixed for good
* 13/1/05
* - use 64 bit arithmetic
* 1/9/09
* - argh nope min/max was broken again for >1CPU in short pipelines on
* some architectures
* 7/9/09
* - rework based on new im__wrapscan() / im_max() ideas for a proper fix
* - gtkdoc comment
* 7/11/11
* - redone as a class
*/
/*
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 <math.h>
#include <vips/vips.h>
#include <vips/internal.h>
#include "statistic.h"
/**
* VipsStats:
* @in: image to scan
* @out: image of statistics
*
* Find many image statistics in a single pass through the data. @out is a
* one-band #VIPS_FORMAT_DOUBLE image
* of 6 columns by n + 1 (where n is number of bands in image @in)
* rows. Columns are statistics, and are, in order: minimum, maximum, sum,
* sum of squares, mean, standard deviation. Row 0 has statistics for all
* bands together, row 1 has stats for band 1, and so on.
*
* See also: #VipsAvg, #VipsMin, and friends.
*
* Returns: 0 on success, -1 on error
*/
typedef struct _VipsStats {
VipsStatistic parent_instance;
VipsImage *out;
or build out and use that as an array?
double **stats;
} VipsStats;
typedef VipsStatisticClass VipsStatsClass;
G_DEFINE_TYPE( VipsStats, vips_stats, VIPS_TYPE_STATISTIC );
static int
vips_stats_build( VipsObject *object )
{
VipsStatistic *statistic = VIPS_STATISTIC( object );
VipsStats *stats = (VipsStats *) object;
gint64 vals;
double average;
if( VIPS_OBJECT_CLASS( vips_stats_parent_class )->build( object ) )
return( -1 );
/* Calculate average. For complex, we accumulate re*re +
* im*im, so we need to sqrt.
*/
vals = (gint64)
vips_image_get_width( statistic->in ) *
vips_image_get_height( statistic->in ) *
vips_image_get_bands( statistic->in );
average = stats->sum / vals;
if( vips_bandfmt_iscomplex( vips_image_get_format( statistic->in ) ) )
average = sqrt( average );
g_object_set( object, "out", average, NULL );
return( 0 );
}
/* Start function: allocate space for a double in which we can accumulate the
* sum for this thread.
*/
static void *
vips_stats_start( VipsStatistic *statistic )
{
return( (void *) g_new0( double, 1 ) );
}
/* Stop function. Add this little sum to the main sum.
*/
static int
vips_stats_stop( VipsStatistic *statistic, void *seq )
{
VipsStats *stats = (VipsStats *) statistic;
double *sum = (double *) seq;
stats->sum += *sum;
g_free( seq );
return( 0 );
}
/* Sum pels in this section.
*/
#define LOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
\
for( i = 0; i < sz; i++ ) \
m += p[i]; \
}
#define CLOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
\
for( i = 0; i < sz; i++ ) { \
double mod; \
\
mod = p[0] * p[0] + p[1] * p[1]; \
p += 2; \
\
m += mod; \
} \
}
/* Loop over region, accumulating a sum in *tmp.
*/
static int
vips_stats_scan( VipsStatistic *statistic, void *seq,
int x, int y, void *in, int n )
{
const int sz = n * vips_image_get_bands( statistic->in );
double *sum = (double *) seq;
int i;
double m;
m = *sum;
/* Now generate code for all types.
*/
switch( vips_image_get_format( statistic->in ) ) {
case VIPS_FORMAT_UCHAR: LOOP( unsigned char ); break;
case VIPS_FORMAT_CHAR: LOOP( signed char ); break;
case VIPS_FORMAT_USHORT: LOOP( unsigned short ); break;
case VIPS_FORMAT_SHORT: LOOP( signed short ); break;
case VIPS_FORMAT_UINT: LOOP( unsigned int ); break;
case VIPS_FORMAT_INT: LOOP( signed int ); break;
case VIPS_FORMAT_FLOAT: LOOP( float ); break;
case VIPS_FORMAT_DOUBLE: LOOP( double ); break;
case VIPS_FORMAT_COMPLEX: CLOOP( float ); break;
case VIPS_FORMAT_DPCOMPLEX: CLOOP( double ); break;
default:
g_assert( 0 );
}
*sum = m;
return( 0 );
}
static void
vips_stats_class_init( VipsStatsClass *class )
{
GObjectClass *gobject_class = (GObjectClass *) class;
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsStatisticClass *sclass = VIPS_STATISTIC_CLASS( class );
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
object_class->nickname = "stats";
object_class->description = _( "find image average" );
object_class->build = vips_stats_build;
sclass->start = vips_stats_start;
sclass->scan = vips_stats_scan;
sclass->stop = vips_stats_stop;
VIPS_ARG_IMAGE( class, "out", 100,
_( "Output" ),
_( "Output image" ),
VIPS_ARGUMENT_REQUIRED_OUTPUT,
G_STRUCT_OFFSET( VipsStats, out ) );
}
static void
vips_stats_init( VipsStats *stats )
{
}
int
vips_stats( VipsImage *in, double *out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "stats", ap, in, out );
va_end( ap );
return( result );
}