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new im_maxpos_avg()

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This commit is contained in:
John Cupitt 2009-09-08 20:32:24 +00:00
parent 5ab5268629
commit 94eaae68ef
3 changed files with 179 additions and 119 deletions
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1
ChangeLog
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@ -31,6 +31,7 @@
- im_avg() works for complex, returning average modulus
- im_maxpos()/im_minpos() are partial and work for complex
- im_max()/im_min() are now convenience functions
- im_maxpos_avg() handles complex and multi-band images
25/3/09 started 7.18.0
- revised version numbers

2
TODO
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@ -1,6 +1,4 @@
- maybe rewrite im_maxpos_avg()
- im_maxpos_vec needs gtkdoc

295
libvips/arithmetic/im_maxpos_avg.c
View File

@ -12,12 +12,15 @@
* - renamed avg as sum, a bit clearer
* 2/9/09
* - gtkdoc comment
* 8/9/08
* - rewrite from im_maxpos()
* - now handles many bands, complex, faster
*/
/*
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
@ -40,40 +43,163 @@
*/
/** HEADERS **/
/*
#define DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_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>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC */
#endif /*WITH_DMALLOC*/
/* A position and maximum.
*/
typedef struct _Maxposavg {
int xpos;
int ypos;
double max;
int occurences;
} Maxposavg;
/** LOCAL TYPES **/
/* New sequence value.
*/
static void *
maxposavg_start( IMAGE *in, void *a, void *b )
{
Maxposavg *global_maxposavg = (Maxposavg *) b;
Maxposavg *maxposavg;
typedef struct {
double x_sum;
double y_sum;
double val;
unsigned int occurrences;
if( !(maxposavg = IM_NEW( NULL, Maxposavg )) )
return( NULL );
*maxposavg = *global_maxposavg;
} pos_avg_t;
return( (void *) maxposavg );
}
/* Merge the sequence value back into the per-call state.
*/
static int
maxposavg_stop( void *seq, void *a, void *b )
{
Maxposavg *global_maxposavg = (Maxposavg *) b;
Maxposavg *maxposavg = (Maxposavg *) seq;
/** LOCAL FUNCTIONS DECLARATIONS **/
/* Merge.
*/
if( maxposavg->max > global_maxposavg->max )
*global_maxposavg = *maxposavg;
static void *maxpos_avg_start( IMAGE *im , void *, void * );
static int maxpos_avg_scan( REGION *reg, void *seq, void *, void * );
static int maxpos_avg_stop( void *seq, void *, void * );
im_free( seq );
return( 0 );
}
/** EXPORTED FUNCTION **/
#define LOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
TYPE m; \
\
m = max; \
\
for( x = 0; x < sz; x++ ) { \
TYPE v = p[x]; \
\
if( v == m ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
} \
else if( v > m ) { \
m = v; \
xpos = r->left + x / reg->im->Bands; \
ypos = r->top + y; \
occurences = 1; \
} \
} \
\
max = m; \
}
#define CLOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
\
for( x = 0; x < sz; x++ ) { \
double mod, re, im; \
\
re = p[0]; \
im = p[1]; \
p += 2; \
mod = re * re + im * im; \
\
if( mod == max ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
} \
else if( mod > max ) { \
max = mod; \
xpos = r->left + x / reg->im->Bands; \
ypos = r->top + y; \
occurences = 1; \
} \
} \
}
/* Loop over region, adding to seq.
*/
static int
maxposavg_scan( REGION *reg, void *seq, void *a, void *b )
{
const Rect *r = &reg->valid;
const int sz = IM_REGION_N_ELEMENTS( reg );
Maxposavg *maxposavg = (Maxposavg *) seq;
int x, y;
double max;
int xpos, ypos, occurences;
xpos = maxposavg->xpos;
ypos = maxposavg->ypos;
max = maxposavg->max;
occurences = maxposavg->occurences;
for( y = 0; y < r->height; y++ ) {
PEL *in = (PEL *) IM_REGION_ADDR( reg, r->left, r->top + y );
switch( reg->im->BandFmt ) {
case IM_BANDFMT_UCHAR: LOOP( unsigned char ); break;
case IM_BANDFMT_CHAR: LOOP( signed char ); break;
case IM_BANDFMT_USHORT: LOOP( unsigned short ); break;
case IM_BANDFMT_SHORT: LOOP( signed short ); break;
case IM_BANDFMT_UINT: LOOP( unsigned int ); break;
case IM_BANDFMT_INT: LOOP( signed int ); break;
case IM_BANDFMT_FLOAT: LOOP( float ); break;
case IM_BANDFMT_DOUBLE: LOOP( double ); break;
case IM_BANDFMT_COMPLEX: CLOOP( float ); break;
case IM_BANDFMT_DPCOMPLEX: CLOOP( double ); break;
default:
g_assert( 0 );
}
}
maxposavg->xpos = xpos;
maxposavg->ypos = ypos;
maxposavg->max = max;
maxposavg->occurences = occurences;
return( 0 );
}
/**
* im_maxpos_avg:
@ -84,117 +210,52 @@ static int maxpos_avg_stop( void *seq, void *, void * );
*
* Function to find the maximum of an image. Returns coords and value at
* double precision. In the event of a draw, returns average of all
* drawing coords, and interpolated value at that position.
* drawing coords.
*
* See also: im_maxpos(), im_min(), im_stats().
*
* Returns: 0 on success, -1 on error
*/
int im_maxpos_avg( IMAGE *im, double *xpos, double *ypos, double *out ){
#define FUNCTION_NAME "im_maxpos_avg"
int
im_maxpos_avg( IMAGE *in, double *xpos, double *ypos, double *out )
{
Maxposavg *global_maxposavg;
pos_avg_t master= { 0.0, 0.0, 0.0, 0 };
if( im_pincheck( in ) ||
im_check_uncoded( "im_maxpos_avg", in ) )
return( -1 );
if( im_pincheck( im ) ||
im_check_uncoded( FUNCTION_NAME, im ) ||
im_check_noncomplex( FUNCTION_NAME, im ) ||
im_check_mono( FUNCTION_NAME, im ) )
return -1;
if( !(global_maxposavg = IM_NEW( in, Maxposavg )) )
return( -1 );
if( im__value( in, &global_maxposavg->max ) )
return( -1 );
global_maxposavg->xpos = 0;
global_maxposavg->ypos = 0;
global_maxposavg->occurences = 1;
if( ! xpos || ! ypos || ! out ){
im_error( FUNCTION_NAME, "%s", _("invalid argument") );
return -1;
}
/* We use square mod for scanning, for speed.
*/
if( im_iscomplex( in ) )
global_maxposavg->max *= global_maxposavg->max;
if( im_iterate( im, maxpos_avg_start, maxpos_avg_scan, maxpos_avg_stop, &master, NULL ) )
return -1;
if( im_iterate( in, maxposavg_start, maxposavg_scan, maxposavg_stop,
in, global_maxposavg ) )
return( -1 );
*xpos= master. x_sum / master. occurrences;
*ypos= master. y_sum / master. occurrences;
/* Back to modulus.
*/
if( im_iscomplex( in ) )
global_maxposavg->max = sqrt( global_maxposavg->max );
return im_point_bilinear( im, *xpos, *ypos, 0, out );
if( xpos )
*xpos = (double) global_maxposavg->xpos /
global_maxposavg->occurences;
if( ypos )
*ypos = (double) global_maxposavg->ypos /
global_maxposavg->occurences;
if( out )
*out = global_maxposavg->max;
#undef FUNCTION_NAME
}
static void *maxpos_avg_start( IMAGE *im, void *a, void *b ){
pos_avg_t *seq;
seq= IM_NEW( NULL, pos_avg_t );
if( ! seq )
return NULL;
seq-> x_sum= 0.0;
seq-> y_sum= 0.0;
seq-> val= 0.0;
seq-> occurrences= 0;
return (void *) seq;
}
/* should be void (always returns 0) */
static int maxpos_avg_scan( REGION *reg, void *vseq, void *a, void *b ) {
pos_avg_t *seq= (pos_avg_t *) vseq;
const int right= reg-> valid. left + reg-> valid. width;
const int bottom= reg-> valid. top + reg-> valid. height;
int x;
int y;
#define LOOPS(type){ \
type *read= (type*) IM_REGION_ADDR( reg, reg-> valid. left, reg-> valid. top ) - reg-> valid. left; \
size_t skip= IM_REGION_LSKIP( reg ) / sizeof( type ); \
\
for( y= reg-> valid. top; y < bottom; ++y, read+= skip ) \
for( x= reg-> valid. left; x < right; ++x ) \
if( !seq-> occurrences || \
read[x] > seq-> val ){ \
seq-> val= read[x]; \
seq-> x_sum= x; \
seq-> y_sum= y; \
seq-> occurrences= 1; \
} \
else if( read[x] == seq-> val ){ \
seq-> x_sum+= x; \
seq-> y_sum+= y; \
++ (seq-> occurrences); \
} \
}
switch( reg-> im-> BandFmt ){
case IM_BANDFMT_CHAR: LOOPS( gint8 ) break;
case IM_BANDFMT_UCHAR: LOOPS( guint8 ) break;
case IM_BANDFMT_SHORT: LOOPS( gint16 ) break;
case IM_BANDFMT_USHORT: LOOPS( guint16 ) break;
case IM_BANDFMT_INT: LOOPS( gint32 ) break;
case IM_BANDFMT_UINT: LOOPS( guint32 ) break;
case IM_BANDFMT_FLOAT: LOOPS( float ) break;
case IM_BANDFMT_DOUBLE: LOOPS( double ) break;
}
return 0;
#undef LOOPS
}
/* should be void (always returns 0) */
static int maxpos_avg_stop( void *vseq, void *a, void *b ) {
pos_avg_t *seq = (pos_avg_t *) vseq;
pos_avg_t *master = (pos_avg_t *) a;
if( !master->occurrences ||
seq-> val > master-> val ){
master-> val= seq-> val;
master-> x_sum= seq-> x_sum;
master-> y_sum= seq-> y_sum;
master-> occurrences= seq-> occurrences;
}
else if( seq-> val == master-> val ){
master-> x_sum+= seq-> x_sum;
master-> y_sum+= seq-> y_sum;
master-> occurrences+= seq-> occurrences;
}
im_free( seq );
return 0;
return( 0 );
}