libvips/libsrc/mosaicing/im_improve.c

194 lines
5.1 KiB
C

/* @(#) Function which improves the selection of tiepoints carried out by
* @(#) im_clinear() until no points have deviation greater than 1 pixel
* @(#) No reference or secondary images are involved
* @(#) Function im_improve assumes that im_clinear has been applied on points
* @(#) No IMAGES are involved in this function and the result is
* @(#) returned in outpoints which is declared as a pointer in the
* @(#) calling routine. Space for outpoints should be allocated in the calling
* @(#) routine
* @(#)
* @(#) int im_improve( inpoints, outpoints )
* @(#) TIE_POINTS *inpoints, *outpoints;
* @(#)
* @(#) Returns 0 on sucess and -1 on error.
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 20/12/1990
* Modified on : 18/04/1991
*/
/*
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 <math.h>
#include <string.h>
#include <vips/vips.h>
#include "mosaic.h"
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
static void
copypoints( TIE_POINTS *pnew, TIE_POINTS *pold )
{
int i;
pnew->reference = pold->reference;
pnew->secondary = pold->secondary;
pnew->deltax = pold->deltax;
pnew->deltay = pold->deltay;
pnew->nopoints = pold->nopoints;
pnew->halfcorsize = pold->halfcorsize;
pnew->halfareasize = pold->halfareasize;
for( i = 0; i < pold->nopoints; i++ ) {
pnew->x_reference[i] = pold->x_reference[i];
pnew->y_reference[i] = pold->y_reference[i];
pnew->x_secondary[i] = pold->x_secondary[i];
pnew->y_secondary[i] = pold->y_secondary[i];
pnew->contrast[i] = pold->contrast[i];
pnew->correlation[i] = pold->correlation[i];
pnew->deviation[i] = pold->deviation[i];
pnew->dx[i] = pold->dx[i];
pnew->dy[i] = pold->dy[i];
}
pnew->l_scale = pold->l_scale;
pnew->l_angle = pold->l_angle;
pnew->l_deltax = pold->l_deltax;
pnew->l_deltay = pold->l_deltay;
}
/* exclude all points with deviation greater or equal to 1.0 pixel
*/
static int
copydevpoints( TIE_POINTS *pnew, TIE_POINTS *pold )
{
int i;
int j;
double thresh_dev,max_dev, min_dev;
double *corr;
min_dev = 9999.0;
max_dev = 0.0;
corr = &pold->correlation[0];
for( i = 0; i < pold->nopoints; i++ )
if( corr[i] > 0.01 ) {
if( pold->deviation[i]/corr[i] < min_dev )
min_dev = pold->deviation[i]/corr[i] ;
if( pold->deviation[i]/corr[i] > max_dev )
max_dev = pold->deviation[i]/corr[i];
}
thresh_dev = min_dev + (max_dev - min_dev)*0.3;
if( thresh_dev <= 1.0 )
thresh_dev = 1.0;
for( i = 0, j = 0; i < pold->nopoints; i++ )
if( pold->correlation[i] > 0.01 )
if( pold->deviation[i]/corr[i] <= thresh_dev ) {
pnew->x_reference[j] = pold->x_reference[i];
pnew->y_reference[j] = pold->y_reference[i];
pnew->x_secondary[j] = pold->x_secondary[i];
pnew->y_secondary[j] = pold->y_secondary[i];
pnew->contrast[j] = pold->contrast[i];
pnew->correlation[j] = pold->correlation[i];
pnew->deviation[j] = pold->deviation[i];
pnew->dx[j] = pold->dx[i];
pnew->dy[j] = pold->dy[i];
j++;
}
pnew->nopoints = j;
for( i = j; i < IM_MAXPOINTS; i++ ) {
pnew->x_reference[i] = 0;
pnew->y_reference[i] = 0;
pnew->x_secondary[i] = 0;
pnew->y_secondary[i] = 0;
pnew->contrast[i] = 0;
pnew->correlation[i] = 0.0;
pnew->deviation[i] = 0.0;
pnew->dx[i] = 0.0;
pnew->dy[i] = 0.0;
}
/* Return non-zero if we changed something.
*/
if( j != pold->nopoints )
return( -1 );
return( 0 );
}
#define SWAP( A, B ) { void *t = (A); A = B; B = t; }
int
im__improve( TIE_POINTS *inpoints, TIE_POINTS *outpoints )
{
TIE_POINTS points1, points2;
TIE_POINTS *p = &points1;
TIE_POINTS *q = &points2;
/* p has the current state - make a new state, q, with only those
* points which have a small deviation.
*/
for( copypoints( p, inpoints );
copypoints( q, p ), copydevpoints( q, p ); ) {
/* If there are only a few left, jump out.
*/
if( q->nopoints < 2 )
break;
/* Fit the model to the new set of points.
*/
if( im__clinear( q ) )
return( -1 );
/* And loop.
*/
SWAP( p, q );
}
/* q has the output - copy to outpoints.
*/
copypoints( outpoints, q );
return( 0 );
}