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992921b012
libvips/libsrc/convolution/im_spcor.c
John Cupitt 992921b012 stuff
2007-10-22 14:09:41 +00:00

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/* @(#) Functions which calculates the correlation coefficient between two
* @(#) images.
* @(#)
* @(#) int im_spcor( IMAGE *in, IMAGE *ref, IMAGE *out )
* @(#)
* @(#) We calculate:
* @(#)
* @(#) sumij (ref(i,j)-mean(ref))(inkl(i,j)-mean(inkl))
* @(#) c(k,l) = ------------------------------------------------
* @(#) sqrt(sumij (ref(i,j)-mean(ref))^2) *
* @(#) sqrt(sumij (inkl(i,j)-mean(inkl))^2)
* @(#)
* @(#) where inkl is the area of in centred at position (k,l).
* @(#)
* @(#) Writes float to out. in and ref must be 1 band uchar, or 1 band
* @(#) ushort.
* @(#)
* @(#) Returns 0 on sucess and -1 on error.
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 02/05/1990
* Modified on :
* 20/2/95 JC
* - updated
* - ANSIfied, a little
* 21/2/95 JC
* - rewritten
* - partialed
* - speed-ups
* - new correlation coefficient (see above), from Niblack "An
* Introduction to Digital Image Processing,", Prentice/Hall, pp 138.
* 4/9/97 JC
* - now does short/ushort as well
* 13/2/03 JC
* - oops, could segv for short images
* 14/4/04 JC
* - sets Xoffset / Yoffset
* 8/3/06 JC
* - use im_embed() with edge stretching on the input, not the output
*/
/*
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 <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Hold global stuff here.
*/
typedef struct {
IMAGE *ref; /* Image we are searching for */
double rmean; /* Mean of search window */
double c1; /* sqrt(sumij (ref(i,j)-mean(ref))^2) */
} SpcorInfo;
typedef struct {
REGION *f;
int *f_cols;
size_t max_cols;
} spcor2_seq;
typedef struct {
IMAGE *w;
gint64 area;
double recip_area;
double mean;
double n_var;
} spcor2_w_inf;
static void *spcor2_start( IMAGE *r, void *a, void *b );
static int spcor2_gen( REGION *r, void *seq, void *a, void *b );
static int spcor2_stop( void *seq, void *a, void *b );
#define LOOP(IN) \
{ \
IN *a = (IN *) p; \
IN *b = (IN *) ref->data; \
int in_lsk = lsk / sizeof( IN ); \
IN *a1, *b1; \
\
/* For each pel in or, loop over ref. First, \
* calculate mean of area in ir corresponding to ref. \
*/ \
for( a1 = a, sum1 = 0, j = 0; j < ref->Ysize; j++, a1 += in_lsk ) \
for( i = 0; i < ref->Xsize; i++ ) \
sum1 += a1[i]; \
imean = (double) sum1 / (ref->Xsize * ref->Ysize); \
\
/* Loop over ir again, this time calculating \
* sum-of-squares-of-differences for this window on \
* ir, and also sum-of-products-of-differences. \
*/ \
for( a1 = a, b1 = b, sum2 = 0.0, sum3 = 0.0, j = 0; \
j < ref->Ysize; j++, a1 += in_lsk, b1 += ref->Xsize ) { \
for( i = 0; i < ref->Xsize; i++ ) { \
/* Reference pel, and input pel. \
*/ \
IN rp = b1[i]; \
IN ip = a1[i]; \
\
/* Accumulate sum-of-squares-of- \
* differences for input image. \
*/ \
double t = ip - imean; \
sum2 += t * t; \
\
/* Accumulate product-of-differences. \
*/ \
sum3 += (rp - inf->rmean) * (ip - imean); \
} \
} \
}
/* spcor generate function.
*/
static int
spcor_gen( REGION *or, void *seq, void *a, void *b )
{
REGION *ir = (REGION *) seq;
SpcorInfo *inf = (SpcorInfo *) b;
IMAGE *ref = inf->ref;
Rect irect;
Rect *r = &or->valid;
int le = r->left;
int to = r->top;
int bo = IM_RECT_BOTTOM(r);
int ri = IM_RECT_RIGHT(r);
int x, y, i, j;
int lsk;
double imean;
double sum1;
double sum2, sum3;
double c2, cc;
/* What part of ir do we need?
*/
irect.left = or->valid.left;
irect.top = or->valid.top;
irect.width = or->valid.width + ref->Xsize - 1;
irect.height = or->valid.height + ref->Ysize - 1;
if( im_prepare( ir, &irect ) )
return( -1 );
lsk = IM_REGION_LSKIP( ir );
/* Loop over or.
*/
for( y = to; y < bo; y++ ) {
float *q = (float *) IM_REGION_ADDR( or, le, y );
for( x = le; x < ri; x++ ) {
PEL *p = (PEL *) IM_REGION_ADDR( ir, x, y );
/* Find sums for this position.
*/
switch( ref->BandFmt ) {
case IM_BANDFMT_UCHAR: LOOP(unsigned char); break;
case IM_BANDFMT_USHORT: LOOP(unsigned short); break;
case IM_BANDFMT_SHORT: LOOP(signed short); break;
default:
error_exit( "im_spcor: internal error #7934" );
/* Keep gcc -Wall happy.
*/
return( -1 );
}
/* Now: calculate correlation coefficient!
*/
c2 = sqrt( sum2 );
cc = sum3 / (inf->c1 * c2);
*q++ = cc;
}
}
return( 0 );
}
/* Pre-calculate stuff for our reference image.
*/
static SpcorInfo *
make_inf( IMAGE *out, IMAGE *ref )
{
SpcorInfo *inf = IM_NEW( out, SpcorInfo );
int sz = ref->Xsize * ref->Ysize;
PEL *p = (PEL *) ref->data;
double s;
int i;
if( !inf )
return( NULL );
/* Pre-calculate stuff on our reference image.
*/
inf->ref = ref;
if( im_avg( inf->ref, &inf->rmean ) )
return( NULL );
/* Find sqrt-of-sum-of-squares-of-differences.
*/
for( s = 0.0, i = 0; i < sz; i++ ) {
double t = (int) p[i] - inf->rmean;
s += t * t;
}
inf->c1 = sqrt( s );
return( inf );
}
int
im_spcor_raw( IMAGE *in, IMAGE *ref, IMAGE *out )
{
SpcorInfo *inf;
/* PIO between in and out; WIO from ref.
*/
if( im_piocheck( in, out ) || im_incheck( ref ) )
return( -1 );
/* Check sizes.
*/
if( in->Xsize < ref->Xsize || in->Ysize < ref->Ysize ) {
im_errormsg( "im_spcor_raw: ref not smaller than in" );
return( -1 );
}
/* Check types.
*/
if( in->Coding != IM_CODING_NONE || in->Bands != 1 ||
ref->Coding != IM_CODING_NONE || ref->Bands != 1 ||
in->BandFmt != ref->BandFmt ) {
im_errormsg( "im_spcor_raw: input not uncoded 1 band" );
return( -1 );
}
if( in->BandFmt != IM_BANDFMT_UCHAR &&
in->BandFmt != IM_BANDFMT_SHORT &&
in->BandFmt != IM_BANDFMT_USHORT ) {
im_errormsg( "im_spcor_raw: input not char/short/ushort" );
return( -1 );
}
/* Prepare the output image.
*/
if( im_cp_descv( out, in, ref, NULL ) )
return( -1 );
out->Bbits = IM_BBITS_FLOAT;
out->BandFmt = IM_BANDFMT_FLOAT;
out->Xsize = in->Xsize - ref->Xsize + 1;
out->Ysize = in->Ysize - ref->Ysize + 1;
/* Pre-calculate some stuff.
*/
if( !(inf = make_inf( out, ref )) )
return( -1 );
/* Set demand hints. FATSTRIP is good for us, as THINSTRIP will cause
* too many recalculations on overlaps.
*/
if( im_demand_hint( out, IM_FATSTRIP, in, NULL ) )
return( -1 );
/* Write the correlation.
*/
if( im_generate( out,
im_start_one, spcor_gen, im_stop_one, in, inf ) )
return( -1 );
out->Xoffset = -ref->Xsize / 2;
out->Yoffset = -ref->Ysize / 2;
return( 0 );
}
/* The above, with the input expanded to make out the same size as in.
*/
int
im_spcor( IMAGE *in, IMAGE *ref, IMAGE *out )
{
IMAGE *t1 = im_open_local( out, "im_spcor intermediate", "p" );
if( !t1 ||
im_embed( in, t1, 1,
ref->Xsize / 2, ref->Ysize / 2,
in->Xsize + ref->Xsize - 1,
in->Ysize + ref->Ysize - 1 ) ||
im_spcor_raw( t1, ref, out ) )
return( -1 );
out->Xoffset = 0;
out->Yoffset = 0;
return( 0 );
}
int
im_spcor2_raw(
IMAGE *f,
IMAGE *w,
IMAGE *r
){
#define FUNCTION_NAME "im_spcor_raw"
DOUBLEMASK *w_stats;
spcor2_w_inf *w_inf;
if( im_piocheck( f, r ) || im_incheck( w ) )
return -1;
if( f-> Xsize < w-> Xsize || f-> Ysize < w-> Ysize ){
im_error( FUNCTION_NAME, "window must be smaller than search area" );
return -1;
}
if( f-> Coding || w-> Coding ){
im_error( FUNCTION_NAME, "uncoded images only" );
return -1;
}
if( 1 != f-> Bands || 1 != w-> Bands ){
im_error( FUNCTION_NAME, "single band images only" );
return -1;
}
if( !( IM_BANDFMT_UCHAR == f-> BandFmt
|| IM_BANDFMT_CHAR == f-> BandFmt
|| IM_BANDFMT_USHORT == f-> BandFmt
|| IM_BANDFMT_SHORT == f-> BandFmt ) ){
im_error( FUNCTION_NAME, "short or char images only" );
return -1;
}
if( f-> BandFmt != w-> BandFmt ){
im_error( FUNCTION_NAME, "band formats must match" );
return -1;
}
if( im_cp_descv( r, f, w, NULL ) )
return -1;
r-> Xsize-= ( w-> Xsize - 1 );
r-> Ysize-= ( w-> Ysize - 1 );
r-> BandFmt= IM_BANDFMT_FLOAT;
r-> Bbits= IM_BBITS_FLOAT;
r-> Xoffset= - w-> Xsize / 2;
r-> Yoffset= - w-> Ysize / 2;
if( im_demand_hint( r, IM_FATSTRIP, f, NULL ) )
return -1;
w_inf= IM_NEW( r, spcor2_w_inf );
w_stats= im_stats( w );
if( ! w_inf || ! w_stats )
return -1;
w_inf-> w= w;
w_inf-> area= w-> Xsize * w-> Ysize;
w_inf-> recip_area= 1.0 / (double) w_inf-> area;
w_inf-> mean= w_stats-> coeff[ 4 ];
w_inf-> n_var= w_stats-> coeff[ 3 ] - w_stats-> coeff[ 2 ] * w_stats-> coeff[ 2 ] * w_inf-> recip_area;
im_free_dmask( w_stats );
return im_generate( r, spcor2_start, spcor2_gen, spcor2_stop, f, w_inf );
#undef FUNCTION_NAME
}
static void *
spcor2_start( IMAGE *r, void *a, void *b ){
IMAGE *f= (IMAGE *) a;
spcor2_seq *seq;
seq= IM_NEW( r, spcor2_seq );
if( ! seq )
return NULL;
seq-> f= im_region_create( f );
seq-> f_cols= NULL;
seq-> max_cols= 0;
if( ! seq-> f )
return NULL;
return seq;
}
static int
spcor2_gen(
REGION *r,
void *vseq, void *a, void *b
){
spcor2_seq *seq= (spcor2_seq *) vseq;
spcor2_w_inf *w_inf= (spcor2_w_inf *) b;
Rect need= {
r-> valid. left,
r-> valid. top,
r-> valid. width + w_inf-> w-> Xsize - 1,
r-> valid. height + w_inf-> w-> Ysize - 1
};
int j;
float *r_data= (float*) IM_REGION_ADDR( r, r-> valid. left, r-> valid. top );
size_t r_skip= IM_REGION_LSKIP( r ) / sizeof( float );
float *r_end= r_data + r-> valid. height * r_skip;
r_skip-= r-> valid. width;
if( im_prepare( seq-> f, & need ) )
return -1;
if( need. width > seq-> max_cols ){
im_free( seq-> f_cols );
seq-> f_cols= IM_ARRAY( NULL, need. width + 1, int ); /* one spare for the last right move */
if( ! seq-> f_cols )
return -1;
seq-> max_cols= need. width;
}
memset( seq-> f_cols, 0, seq-> max_cols * sizeof( int ) );
#define LOOPS(TYPE) { \
TYPE *f_start= (TYPE*) IM_REGION_ADDR( seq-> f, need. left, need. top ); \
size_t f_skip= IM_REGION_LSKIP( seq-> f ) / sizeof( TYPE ); \
size_t f_row_skip= f_skip - r-> valid. width; \
size_t f_win_skip= f_skip - w_inf-> w-> Xsize; \
\
TYPE *f_win_end= f_start; \
TYPE *f_stop= f_win_end + f_skip * w_inf-> w-> Ysize; \
\
for( ; f_win_end < f_stop; f_win_end+= f_skip ) \
for( j= 0; j < need. width; ++j ) \
seq-> f_cols[ j ]+= f_win_end[ j ]; \
\
for( ; r_data < r_end; r_data+= r_skip, f_start+= f_row_skip, f_win_end+= f_skip ){ \
double f_mean= 0.0; \
\
for( j= 0; j < w_inf-> w-> Xsize; ++j ) \
f_mean+= seq-> f_cols[ j ]; \
\
f_mean*= w_inf-> recip_area; \
\
for( j= 0; j < r-> valid. width; ++f_start, ++r_data, \
f_mean+= ( seq-> f_cols[ w_inf-> w-> Xsize + j ] - seq-> f_cols[ j ] ) * w_inf-> recip_area, \
++j ){ \
\
double num_sum= 0.0; \
double den_sum= 0.0; \
TYPE *w_data= (TYPE*) w_inf-> w-> data; \
TYPE *w_end= w_data + w_inf-> area; \
TYPE *w_stop; \
TYPE *f_data= f_start; \
\
for( ; w_data < w_end; f_data+= f_win_skip ) \
for( w_stop= w_data + w_inf-> w-> Xsize; w_data < w_stop; ++w_data, ++f_data ){ \
\
double f_term= *f_data - f_mean; \
\
num_sum+= f_term * ( *w_data - w_inf-> mean ); \
den_sum+= f_term * f_term; \
} \
\
*r_data= num_sum * pow( den_sum * w_inf-> n_var, -0.5 ); \
} \
\
if( r_data + r_skip < r_end ) \
for( j= 0; j < need. width; ++j ) \
seq-> f_cols[ j ]+= f_win_end[ j ] - f_start[ j ]; \
} \
}
switch( w_inf-> w-> BandFmt ){
case IM_BANDFMT_UCHAR: LOOPS( guint8 ) break;
case IM_BANDFMT_CHAR: LOOPS( gint8 ) break;
case IM_BANDFMT_USHORT: LOOPS( guint16 ) break;
case IM_BANDFMT_SHORT: LOOPS( gint16 ) break;
}
#undef LOOPS
return 0;
}
static int
spcor2_stop( void *vseq, void *a, void *b ){
spcor2_seq *seq= (spcor2_seq *) vseq;
IM_FREEF( im_region_free, seq-> f );
IM_FREE( seq-> f_cols );
return 0;
}
int
im_spcor2( IMAGE *in, IMAGE *ref, IMAGE *out )
{
IMAGE *t1 = im_open_local( out, "im_spcor2 intermediate", "p" );
if( !t1 ||
im_embed( in, t1, 1,
ref->Xsize / 2, ref->Ysize / 2,
in->Xsize + ref->Xsize - 1,
in->Ysize + ref->Ysize - 1 ) ||
im_spcor2_raw( t1, ref, out ) )
return( -1 );
out->Xoffset = 0;
out->Yoffset = 0;
return( 0 );
}
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