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/*
# This file is part of the Astrometry.net suite.
# Licensed under a 3-clause BSD style license - see LICENSE
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "os-features.h"
#include "fits-guess-scale.h"
#include "anqfits.h"
#include "sip.h"
#include "sip_qfits.h"
#include "starutil.h"
#include "errors.h"
#include "log.h"
#include "mathutil.h"
int fits_guess_scale(const char* infn,
sl** p_methods, dl** p_scales) {
qfits_header* hdr;
hdr = anqfits_get_header2(infn, 0);
if (!hdr) {
ERROR("Failed to read FITS header");
return -1;
}
fits_guess_scale_hdr(hdr, p_methods, p_scales);
qfits_header_destroy(hdr);
return 0;
}
static void addscale(sl* methods, dl* scales,
const char* method, double scale) {
if (methods)
sl_append(methods, method);
if (scales)
dl_append(scales, scale);
}
void fits_guess_scale_hdr(const qfits_header* hdr,
sl** p_methods, dl** p_scales) {
sip_t sip;
double val;
anbool gotsip = FALSE;
char* errstr;
sl* methods = NULL;
dl* scales = NULL;
if (p_methods) {
if (!*p_methods)
*p_methods = sl_new(4);
methods = *p_methods;
}
if (p_scales) {
if (!*p_scales)
*p_scales = dl_new(4);
scales = *p_scales;
}
memset(&sip, 0, sizeof(sip_t));
errors_start_logging_to_string();
if (sip_read_header(hdr, &sip)) {
val = sip_pixel_scale(&sip);
if (val != 0.0) {
addscale(methods, scales, "sip", val);
gotsip = TRUE;
}
}
errstr = errors_stop_logging_to_string("\n ");
logverb("fits-guess-scale: failed to read SIP/TAN header:\n %s\n", errstr);
free(errstr);
if (!gotsip) {
// it might have a correct CD matrix but be missing other parts (eg CRVAL)
double cd11, cd12, cd21, cd22;
double errval = -LARGE_VAL;
cd11 = qfits_header_getdouble(hdr, "CD1_1", errval);
cd12 = qfits_header_getdouble(hdr, "CD1_2", errval);
cd21 = qfits_header_getdouble(hdr, "CD2_1", errval);
cd22 = qfits_header_getdouble(hdr, "CD2_2", errval);
if ((cd11 != errval) && (cd12 != errval) && (cd21 != errval) && (cd22 != errval)) {
val = cd11 * cd22 - cd12 * cd21;
if (val != 0.0)
addscale(methods, scales, "cd", sqrt(fabs(val)));
}
}
val = qfits_header_getdouble(hdr, "PIXSCALE", -1.0);
if (val != -1.0)
addscale(methods, scales, "pixscale", val);
/* Why all this?
val = qfits_header_getdouble(hdr, "PIXSCAL1", -1.0);
if (val != -1.0) {
if (val != 0.0) {
printf("scale pixscal1 %g\n", val);
} else {
val = atof(qfits_pretty_string(qfits_header_getstr(hdr, "PIXSCAL1")));
if (val != 0.0) {
printf("scale pixscal1 %g\n", val);
}
}
}
*/
val = qfits_header_getdouble(hdr, "PIXSCAL1", 0.0);
if (val != 0.0)
addscale(methods, scales, "pixscal1", val);
val = qfits_header_getdouble(hdr, "PIXSCAL2", 0.0);
if (val != 0.0)
addscale(methods, scales, "pixscal2", val);
val = qfits_header_getdouble(hdr, "PLATESC", 0.0);
if (val != 0.0)
addscale(methods, scales, "platesc", val);
val = qfits_header_getdouble(hdr, "CCDSCALE", 0.0);
if (val != 0.0)
addscale(methods, scales, "ccdscale", val);
val = qfits_header_getdouble(hdr, "CDELT1", 0.0);
if (val != 0.0)
addscale(methods, scales, "cdelt1", 3600.0 * fabs(val));
}
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