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im_maxpos_avg() avoids NaN

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This commit is contained in:
John Cupitt 2015-03-26 17:16:52 +00:00
parent 9552315e80
commit 09b81b7580
2 changed files with 84 additions and 63 deletions
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1
ChangeLog
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@ -1,4 +1,5 @@
26/3/15 started 7.42.4
- im_maxpos_avg() avoids NaN
6/2/15 started 7.42.3
- bump version for back-compat ABI change

146
libvips/deprecated/im_maxpos_avg.c
View File

@ -17,6 +17,8 @@
* - now handles many bands, complex, faster
* 27/7/14
* - fix a race ... did not merge states if max was equal
* 26/3/15
* - avoid NaN
*/
/*
@ -62,32 +64,15 @@
#include <vips/vips.h>
#include <vips/internal.h>
/* Get the value of pixel (0, 0). Use this to init the min/max value for
* im_max()/im_stats()/etc.
*/
int
im__value( IMAGE *im, double *value )
{
IMAGE *t;
if( !(t = im_open( "im__value", "p" )) )
return( -1 );
if( im_extract_areabands( im, t, 0, 0, 1, 1, 0, 1 ) ||
im_avg( t, value ) ) {
im_close( t );
return( -1 );
}
im_close( t );
return( 0 );
}
/* A position and maximum.
*/
typedef struct _Maxposavg {
int xpos;
int ypos;
double max;
/* occurences == 0 means we found no points, or we are uninitialised.
*/
int occurences;
} Maxposavg;
@ -116,7 +101,9 @@ maxposavg_stop( void *seq, void *a, void *b )
/* Merge.
*/
if( maxposavg->max > global_maxposavg->max )
if( maxposavg->occurences == 0 ) {
}
else if( maxposavg->max > global_maxposavg->max )
*global_maxposavg = *maxposavg;
else if( maxposavg->max == global_maxposavg->max ) {
global_maxposavg->xpos += maxposavg->xpos;
@ -129,7 +116,9 @@ maxposavg_stop( void *seq, void *a, void *b )
return( 0 );
}
#define LOOP( TYPE ) { \
/* int loop.
*/
#define ILOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
TYPE m; \
\
@ -138,22 +127,53 @@ maxposavg_stop( void *seq, void *a, void *b )
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 ) { \
if( occurences == 0 || v > m ) { \
m = v; \
xpos = r->left + x / reg->im->Bands; \
ypos = r->top + y; \
occurences = 1; \
} \
else if( v == m ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
} \
} \
\
max = m; \
}
/* float/double loop ... avoid NaN.
*/
#define FLOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
TYPE m; \
\
m = max; \
\
for( x = 0; x < sz; x++ ) { \
TYPE v = p[x]; \
\
if( isnan( v ) ) { \
} \
else if( occurences == 0 || v > m ) { \
m = v; \
xpos = r->left + x / reg->im->Bands; \
ypos = r->top + y; \
occurences = 1; \
} \
else if( v == m ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
} \
} \
\
max = m; \
}
/* complex/dpcomplex loop ... avoid NaN.
*/
#define CLOOP( TYPE ) { \
TYPE *p = (TYPE *) in; \
\
@ -165,17 +185,19 @@ maxposavg_stop( void *seq, void *a, void *b )
p += 2; \
mod = re * re + im * im; \
\
if( mod == max ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
if( isnan( mod ) ) { \
} \
else if( mod > max ) { \
else if( occurences == 0 || mod > max ) { \
max = mod; \
xpos = r->left + x / reg->im->Bands; \
ypos = r->top + y; \
occurences = 1; \
} \
else if( mod == max ) { \
xpos += r->left + x / reg->im->Bands; \
ypos += r->top + y; \
occurences += 1; \
} \
} \
}
@ -201,14 +223,14 @@ maxposavg_scan( REGION *reg, void *seq, void *a, void *b, gboolean *stop )
VipsPel *in = VIPS_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_UCHAR: ILOOP( unsigned char ); break;
case IM_BANDFMT_CHAR: ILOOP( signed char ); break;
case IM_BANDFMT_USHORT: ILOOP( unsigned short ); break;
case IM_BANDFMT_SHORT: ILOOP( signed short ); break;
case IM_BANDFMT_UINT: ILOOP( unsigned int ); break;
case IM_BANDFMT_INT: ILOOP( signed int ); break;
case IM_BANDFMT_FLOAT: FLOOP( float ); break;
case IM_BANDFMT_DOUBLE: FLOOP( double ); break;
case IM_BANDFMT_COMPLEX: CLOOP( float ); break;
case IM_BANDFMT_DPCOMPLEX: CLOOP( double ); break;
@ -251,34 +273,32 @@ im_maxpos_avg( IMAGE *in, double *xpos, double *ypos, double *out )
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;
/* We use square mod for scanning, for speed.
*/
if( vips_band_format_iscomplex( in->BandFmt ) )
global_maxposavg->max *= global_maxposavg->max;
global_maxposavg->occurences = 0;
if( vips_sink( in, maxposavg_start, maxposavg_scan, maxposavg_stop,
in, global_maxposavg ) )
return( -1 );
/* Back to modulus.
*/
if( vips_band_format_iscomplex( in->BandFmt ) )
global_maxposavg->max = sqrt( global_maxposavg->max );
if( global_maxposavg->occurences == 0 ) {
*xpos = nan("");
*ypos = nan("");
*out = nan("");
}
else {
/* Back to modulus.
*/
if( vips_band_format_iscomplex( in->BandFmt ) )
global_maxposavg->max = sqrt( global_maxposavg->max );
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;
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;
}
return( 0 );
}