1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
# This file is part of the Astrometry.net suite.
# Licensed under a 3-clause BSD style license - see LICENSE
*/
#include <stdio.h>
#include <assert.h>
#include "cutest.h"
#include "index.h"
#include "solver.h"
#include "xylist.h"
#include "sip.h"
#include "sip-utils.h"
#include "bl.h"
#include "log.h"
#include "errors.h"
#include "sip_qfits.h"
/*
- build-astrometry-index -d 3 -o index-9918.fits -P 18 -S mag -B 0.1 -s 0 -r 1 -I 9918 -M -i demo/tycho2-mag6.fits
- echo -e 'add_path .\ninparallel\nindex index-9918.fits' > 99.cfg
- solve-field --config 99.cfg demo/apod4.jpg --continue --keep-xylist apod4.xy
- solve-field --config 99.cfg --continue apod4.xy --width 719 --height 507
*/
void test_predistort(CuTest* ct) {
// core Astrometry solver parameters
solver_t* solver;
int imagew, imageh;
double imagecx, imagecy;
double deg_width_min = 30;
double deg_width_max = 40;
char* xyfn = "apod4.xy";
char* indexfn = "index-9918.fits";
int loglvl = LOG_MSG;
//loglvl++;
loglvl++;
log_init(loglvl);
imagew = 719;
imageh = 507;
imagecx = (imagew - 1.0)/2.0;
imagecy = (imageh - 1.0)/2.0;
// Here we initialize the core astrometry solver struct, telling
// it about the possible range of image scales.
solver = solver_new();
double qsf_min = 0.1;
// don't try teeny-tiny quads.
solver->quadsize_min = qsf_min * MIN(imagew, imageh);
// compute scale range in arcseconds per pixel.
// set the solver's "funits" = field (image) scale units
solver->funits_lower = 3600. * deg_width_min / (double)imagew;
solver->funits_upper = 3600. * deg_width_max / (double)imagew;
solver_set_keep_logodds(solver, log(1e12));
solver->logratio_toprint = log(1e6);
solver->endobj = 20;
xylist_t* xyls = xylist_open(xyfn);
starxy_t* xy = xylist_read_field(xyls, NULL);
// Feed the image source coordinates to the solver...
//starxy_set_flux_array(field, starflux);
//starxy_sort_by_flux(field);
solver_set_field(solver, xy);
solver_set_field_bounds(solver, 0, imagew, 0, imageh);
index_t* index = index_load(indexfn, 0, NULL);
solver_add_index(solver, index);
solver->distance_from_quad_bonus = TRUE;
solver->do_tweak = TRUE;
solver->tweak_aborder = 2;
solver->tweak_abporder = 4;
solver_run(solver);
CuAssert(ct, "Should solve on undistorted field", solver->best_match_solves);
double ra, dec;
double pscale;
tan_t* wcs;
logmsg("Solved using index %s with odds ratio %g\n",
solver->best_index->indexname,
solver->best_match.logodds);
// WCS is solver->best_match.wcstan
wcs = &(solver->best_match.wcstan);
// center
tan_pixelxy2radec(wcs, imagecx, imagecy, &ra, &dec);
pscale = tan_pixel_scale(wcs);
logmsg("Image center is RA,Dec = (%g,%g) degrees, size is %.2g x %.2g arcmin.\n",
ra, dec, arcsec2arcmin(pscale * imagew), arcsec2arcmin(pscale * imageh));
sip_write_to_file(solver->best_match.sip, "undistorted-sip.wcs");
//////////////////////////////////////////////////////////
solver_reset_best_match(solver);
solver_reset_counters(solver);
sip_t distortion;
memset(&distortion, 0, sizeof(sip_t));
distortion.wcstan.imagew = imagew;
distortion.wcstan.imageh = imageh;
distortion.wcstan.crpix[0] = imagecx;
distortion.wcstan.crpix[1] = imagecy;
distortion.a_order = 2;
distortion.b_order = 2;
distortion.a[2][0] = 2e-4;
// inverse
distortion.ap_order = 4;
distortion.bp_order = 4;
sip_compute_inverse_polynomials(&distortion, 0, 0, 0, 0, 0, 0);
// Compute distorted star positions
starxy_t* xy_dist;
int i,N;
N = xy->N;
xy_dist = starxy_new(N, FALSE, FALSE);
double total_dx = 0;
double total_dy = 0;
for (i=0; i<N; i++) {
double dx,dy;
sip_pixel_distortion(&distortion, xy->x[i], xy->y[i], &dx, &dy);
xy_dist->x[i] = dx;
xy_dist->y[i] = dy;
//printf("x,y %.1f, %.1f -> %.1f, %.1f (delta %.1f, %.1f)\n",
//xy->x[i], xy->y[i], dx, dy, dx - xy->x[i], dy - xy->y[i]);
total_dx += fabs(dx - xy->x[i]);
total_dy += fabs(dy - xy->y[i]);
}
total_dx /= N;
total_dy /= N;
printf("Average distortion in x,y: %.1f, %.1f\n", total_dx, total_dy);
// TEST undoing the distortion.
{
starxy_t* xy_undist;
xy_undist = starxy_subset(xy_dist, starxy_n(xy_dist));
total_dx = 0;
total_dy = 0;
for (i=0; i<N; i++) {
double dx,dy;
sip_pixel_undistortion(&distortion, xy_undist->x[i], xy_undist->y[i], &dx, &dy);
xy_undist->x[i] = dx;
xy_undist->y[i] = dy;
total_dx += fabs(dx - xy->x[i]);
total_dy += fabs(dy - xy->y[i]);
}
total_dx /= N;
total_dy /= N;
printf("After undistorting: avg error in x,y: %.1f, %.1f\n", total_dx, total_dy);
}
// avoid solver freeing "xy".
solver->fieldxy = NULL;
solver_set_field(solver, xy_dist);
solver_set_field_bounds(solver, 0, imagew, 0, imageh);
solver_run(solver);
CuAssert(ct, "Should fail on distorted field", !solver->best_match_solves);
solver->predistort = &distortion;
// avoid solver freeing "xy_dist", but we still want to reset the preprocessing.
solver->fieldxy_orig = NULL;
solver_set_field(solver, xy_dist);
solver_set_field_bounds(solver, 0, imagew, 0, imageh);
solver->do_tweak = TRUE;
solver->tweak_aborder = 2;
solver->tweak_abporder = 4;
solver_reset_best_match(solver);
solver_reset_counters(solver);
solver_run(solver);
CuAssert(ct, "Should solve given correct predistortion", solver->best_match_solves);
printf("Writing SIP solution...\n");
//solver->best_match.wcstan;
sip_write_to_file(solver->best_match.sip, "distorted-sip.wcs");
}
|
