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.
*/
IM_SWAP( void *, p, q );
}
/* q has the output - copy to outpoints.
*/
copypoints( outpoints, q );
return( 0 );
}
int
im__initialize( TIE_POINTS *points )
{
if( im__clinear( points ) ) {
/* im_clinear failed! Set some sensible fallback values.
*/
int i, j;
double xdelta, ydelta, max_cor;
double a1, a2;
int *xref = &points->x_reference[0];
int *yref = &points->y_reference[0];
int *xsec = &points->x_secondary[0];
int *ysec = &points->y_secondary[0];
double *corr = &points->correlation[0];
double *dx = &points->dx[0];
double *dy = &points->dy[0];
int npt = points->nopoints;
max_cor = 0.0;
for( i = 0; i < npt; i++ )
if( corr[i] > max_cor )
max_cor = corr[i];
max_cor = max_cor - 0.04;
xdelta = 0.0;
ydelta = 0.0;
j = 0;
for( i = 0; i < npt; i++ )
if( corr[i] >= max_cor ) {
xdelta += xsec[i] - xref[i];
ydelta += ysec[i] - yref[i];
++j;
}
xdelta = xdelta/j;
ydelta = ydelta/j;
for(i = 0; i < npt; i++ ) {
dx[i] = (xsec[i] - xref[i]) - xdelta;
dy[i] = (ysec[i] - yref[i]) - ydelta;
}
for( i = 0; i < npt; i++ ) {
a1 = dx[i];
a2 = dy[i];
points->deviation[i] = sqrt( a1*a1 + a2*a2 );
}
points->l_scale = 1.0;
points->l_angle = 0.0;
points->l_deltax = xdelta;
points->l_deltay = ydelta;
}
return( 0 );
}