libvips/libsrc/arithmetic/im_maxpos_vec.c
John Cupitt 57f24c63d6 stuff
2007-10-20 01:00:06 +00:00

471 lines
13 KiB
C

/* @(#) Find the coordinates and values of the n maxima of an image.
* @(#)
* @(#) int im_maxpos_vec(
* @(#) IMAGE *im,
* @(#) int *xpos,
* @(#) int *ypos,
* @(#) double *maxima,
* @(#) int n
* @(#) );
* @(#)
* @(#) Find the coordinates and values of the n minima of an image.
* @(#)
* @(#) int im_minpos_vec(
* @(#) IMAGE *im,
* @(#) int *xpos,
* @(#) int *ypos,
* @(#) double *minima,
* @(#) int n
* @(#) );
* @(#)
*
* Copyright: 2006, The Nottingham Trent University
* Copyright: 2006, Tom Vajzovic
*
* Author: Tom Vajzovic
*
* Written on: 2006-09-01
*/
/*
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
*/
/** HEADERS **/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <vips/intl.h>
#include <stdlib.h>
#include <float.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC */
/** TYPE DEFINITIONS **/
typedef struct {
int *xs;
int *ys;
double *vals;
int *ptrs;
int start;
} maxpos_list;
/** LOCAL FUNCTIONS DECLARATIONS **/
static maxpos_list *maxpos_list_alloc( int n );
static void maxpos_list_free( maxpos_list *list );
static void maxpos_list_init( maxpos_list *list, int n );
static void *maxpos_vec_start( IMAGE *unrequired, void *, void * );
static int maxpos_vec_scan( REGION *reg, void *seq, void *, void * );
static void add_to_maxpos_list( maxpos_list *list, int x, int y, double val );
static int maxpos_vec_stop( void *seq, void *, void * );
static void minpos_list_init( maxpos_list *list, int n );
static void *minpos_vec_start( IMAGE *unrequired, void *, void * );
static int minpos_vec_scan( REGION *reg, void *seq, void *, void * );
static void add_to_minpos_list( maxpos_list *list, int x, int y, double val );
static int minpos_vec_stop( void *seq, void *, void * );
/** EXPORTED FUNCTIONS **/
int im_maxpos_vec( IMAGE *im, int *xpos, int *ypos, double *maxima, int n ){
#define FUNCTION_NAME "im_maxpos_vec"
/* number of sequences used is beyond my control at this level, but I note that */
/* effeciency decreases as more sequences are used - speed may still increase */
int result;
int *pointers= im_malloc( NULL, n * sizeof( int* ) );
maxpos_list master_list= { xpos, ypos, maxima, pointers, 0 };
if( im_pincheck( im ) )
return -1;
if( !pointers )
return -1;
if( ! ( im_isint( im ) || im_isfloat( im ) ) ){
im_error( FUNCTION_NAME, _( "scalar images only" ) );
return -1;
}
if( 1 != im-> Bands ){
im_error( FUNCTION_NAME, _( "single band images only" ) );
return -1;
}
if( IM_CODING_NONE != im-> Coding ){
im_error( FUNCTION_NAME, _( "uncoded images only" ) );
return -1;
}
if( ! xpos || ! ypos || ! maxima || n < 1 ){
im_error( FUNCTION_NAME, _( "invalid argument" ) );
return -1;
}
maxpos_list_init( &master_list, n );
result= im_iterate( im, maxpos_vec_start, maxpos_vec_scan, maxpos_vec_stop, &n, &master_list );
im_free( pointers );
return result;
#undef FUNCTION_NAME
}
int im_minpos_vec( IMAGE *im, int *xpos, int *ypos, double *minima, int n ){
#define FUNCTION_NAME "im_minpos_vec"
/* number of sequences used is beyond my control at this level, but I note that */
/* effeciency decreases as more sequences are used - speed may still increase */
int result;
int *pointers= im_malloc( NULL, n * sizeof( int* ) );
maxpos_list master_list= { xpos, ypos, minima, pointers, 0 };
if( im_pincheck( im ) )
return -1;
if( !pointers )
return -1;
if( ! ( im_isint( im ) || im_isfloat( im ) ) ){
im_error( FUNCTION_NAME, _( "scalar images only" ) );
return -1;
}
if( 1 != im-> Bands ){
im_error( FUNCTION_NAME, _( "single band images only" ) );
return -1;
}
if( IM_CODING_NONE != im-> Coding ){
im_error( FUNCTION_NAME, _( "uncoded images only" ) );
return -1;
}
if( ! xpos || ! ypos || ! minima || n < 1 ){
im_error( FUNCTION_NAME, _( "invalid argument" ) );
return -1;
}
minpos_list_init( &master_list, n );
result= im_iterate( im, minpos_vec_start, minpos_vec_scan, minpos_vec_stop, &n, &master_list );
im_free( pointers );
return result;
#undef FUNCTION_NAME
}
/** LOCAL FUNCTION DEFINITIONS **/
static maxpos_list *maxpos_list_alloc( int n ){
maxpos_list *list= im_malloc( NULL, sizeof( maxpos_list ) );
if( ! list )
return NULL;
list-> xs= im_malloc( NULL, 3 * n * sizeof( int ) );
list-> vals= im_malloc( NULL, n * sizeof( double ) );
if( ! list-> xs || ! list-> vals ){
im_free( list-> xs );
im_free( list-> vals );
im_free( list );
return NULL;
}
list-> ys= list-> xs + n;
list-> ptrs= list-> ys + n;
return list;
}
static void maxpos_list_free( maxpos_list *list ){
im_free( list-> xs );
im_free( list-> vals );
im_free( list );
}
static void maxpos_list_init( maxpos_list *list, int n ){
int i;
for( i= 0; i < n; ++i ){
list-> xs[ i ]= 0;
list-> ys[ i ]= 0;
list-> vals[ i ]= 0;
list-> ptrs[ i ]= i + 1;
}
list-> ptrs[ n - 1 ]= -1;
list-> start= 0;
}
static void *maxpos_vec_start( IMAGE *unrequired, void *a, void *b ){
int *n = (int *) a;
maxpos_list *list= maxpos_list_alloc( *n );
if( ! list )
return NULL;
maxpos_list_init( list, *n );
return list;
}
static int maxpos_vec_scan( REGION *reg, void *seq, void *a, void *b ){
maxpos_list *list = (maxpos_list *) seq;
#define MAXPOS_VEC_SCAN( type ){ \
\
int y= reg-> valid. top; \
int x; \
int ymax= y + reg-> valid. height; \
int xmax= reg-> valid. left + reg-> valid. width; \
\
type *row= (type*)IM_REGION_ADDR( reg, reg-> valid. left, y ) - reg-> valid. left; \
size_t skip= IM_REGION_LSKIP( reg ) / sizeof( type ); \
\
for( ; y < ymax; ++y, row+= skip ) \
for( x= reg-> valid. left; x < xmax; ++x ) \
if( row[ x ] > list-> vals[ list-> start ] ) \
add_to_maxpos_list( list, x, y, row[ x ] ); \
}
switch( reg-> im-> BandFmt ){
case IM_BANDFMT_UCHAR: MAXPOS_VEC_SCAN( guint8 ) break;
case IM_BANDFMT_CHAR: MAXPOS_VEC_SCAN( gint8 ) break;
case IM_BANDFMT_USHORT: MAXPOS_VEC_SCAN( guint16 ) break;
case IM_BANDFMT_SHORT: MAXPOS_VEC_SCAN( gint16 ) break;
case IM_BANDFMT_UINT: MAXPOS_VEC_SCAN( guint32 ) break;
case IM_BANDFMT_INT: MAXPOS_VEC_SCAN( gint32 ) break;
case IM_BANDFMT_FLOAT: MAXPOS_VEC_SCAN( float ) break;
case IM_BANDFMT_DOUBLE: MAXPOS_VEC_SCAN( double ) break;
}
#undef MAXPOS_VEC_SCAN
return 0;
}
static void add_to_maxpos_list( maxpos_list *list, int x, int y, double val ){
int pointer= list-> start;
while( -1 != list-> ptrs[ pointer ] && val > list-> vals[ list-> ptrs[ pointer ] ] )
pointer= list-> ptrs[ pointer ];
list-> xs[ list-> start ]= x;
list-> ys[ list-> start ]= y;
list-> vals[ list-> start ]= val;
if( list-> start != pointer ){
/* we are adding mid-chain not at the very bottom */
int second= list-> ptrs[ list-> start ];
list-> ptrs[ list-> start ]= list-> ptrs[ pointer ];
list-> ptrs[ pointer ]= list-> start;
list-> start= second;
}
}
static int maxpos_vec_stop( void *seq, void *a, void *b ){
/* reverse list */
maxpos_list *list = (maxpos_list *) seq;
maxpos_list *master_list = (maxpos_list *) b;
int prev= -1;
int pointer= list-> start;
while( -1 != list-> ptrs[ pointer ] ){
int next= list-> ptrs[ pointer ];
list-> ptrs[ pointer ]= prev;
prev= pointer;
pointer= next;
}
list-> ptrs[ pointer ]= prev;
list-> start= pointer;
/* add to main list */
for( ; -1 != pointer; pointer= list-> ptrs[ pointer ] )
/* loop over all the ones found in this sequence */
if( list-> vals[ pointer ] > master_list-> vals[ master_list-> start ] )
add_to_maxpos_list( master_list, list-> xs[ pointer ], list-> ys[ pointer ], list-> vals[ pointer ] );
else
break;
/* since we are now high->low, if this one isn't big enough, none of the rest are */
maxpos_list_free( list );
return 0;
}
static void minpos_list_init( maxpos_list *list, int n ){
int i;
for( i= 0; i < n; ++i ){
list-> xs[ i ]= 0;
list-> ys[ i ]= 0;
list-> vals[ i ]= DBL_MAX;
list-> ptrs[ i ]= i + 1;
}
list-> ptrs[ n - 1 ]= -1;
list-> start= 0;
}
static void *minpos_vec_start( IMAGE *unrequired, void *a, void *b ){
int *n = (int *) a;
maxpos_list *list= maxpos_list_alloc( *n );
if( ! list )
return NULL;
minpos_list_init( list, *n );
return list;
}
static int minpos_vec_scan( REGION *reg, void *seq, void *a, void *b ){
maxpos_list *list = (maxpos_list *) seq;
#define MINPOS_VEC_SCAN( type ){ \
\
int y= reg-> valid. top; \
int x; \
int ymax= y + reg-> valid. height; \
int xmax= reg-> valid. left + reg-> valid. width; \
\
type *row= (type*)IM_REGION_ADDR( reg, reg-> valid. left, y ) - reg-> valid. left; \
size_t skip= IM_REGION_LSKIP( reg ) / sizeof( type ); \
\
for( ; y < ymax; ++y, row+= skip ) \
for( x= reg-> valid. left; x < xmax; ++x ) \
if( row[ x ] < list-> vals[ list-> start ] ) \
add_to_minpos_list( list, x, y, row[ x ] ); \
}
switch( reg-> im-> BandFmt ){
case IM_BANDFMT_UCHAR: MINPOS_VEC_SCAN( guint8 ) break;
case IM_BANDFMT_CHAR: MINPOS_VEC_SCAN( gint8 ) break;
case IM_BANDFMT_USHORT: MINPOS_VEC_SCAN( guint16 ) break;
case IM_BANDFMT_SHORT: MINPOS_VEC_SCAN( gint16 ) break;
case IM_BANDFMT_UINT: MINPOS_VEC_SCAN( guint32 ) break;
case IM_BANDFMT_INT: MINPOS_VEC_SCAN( gint32 ) break;
case IM_BANDFMT_FLOAT: MINPOS_VEC_SCAN( float ) break;
case IM_BANDFMT_DOUBLE: MINPOS_VEC_SCAN( double ) break;
}
#undef MINPOS_VEC_SCAN
return 0;
}
static void add_to_minpos_list( maxpos_list *list, int x, int y, double val ){
int pointer= list-> start;
while( -1 != list-> ptrs[ pointer ] && val < list-> vals[ list-> ptrs[ pointer ] ] )
pointer= list-> ptrs[ pointer ];
list-> xs[ list-> start ]= x;
list-> ys[ list-> start ]= y;
list-> vals[ list-> start ]= val;
if( list-> start != pointer ){
/* we are adding mid-chain not at the very bottom */
int second= list-> ptrs[ list-> start ];
list-> ptrs[ list-> start ]= list-> ptrs[ pointer ];
list-> ptrs[ pointer ]= list-> start;
list-> start= second;
}
}
static int minpos_vec_stop( void *seq, void *a, void *b ){
/* reverse list */
maxpos_list *list = (maxpos_list *) seq;
maxpos_list *master_list = (maxpos_list *) b;
int prev= -1;
int pointer= list-> start;
while( -1 != list-> ptrs[ pointer ] ){
int next= list-> ptrs[ pointer ];
list-> ptrs[ pointer ]= prev;
prev= pointer;
pointer= next;
}
list-> ptrs[ pointer ]= prev;
list-> start= pointer;
/* add to main list */
for( ; -1 != pointer; pointer= list-> ptrs[ pointer ] )
/* loop over all the ones found in this sequence */
if( list-> vals[ pointer ] < master_list-> vals[ master_list-> start ] )
add_to_minpos_list( master_list, list-> xs[ pointer ], list-> ys[ pointer ], list-> vals[ pointer ] );
else
break;
/* since we are now high->low, if this one isn't big enough, none of the rest are */
maxpos_list_free( list );
return 0;
}