sip_t* sip_from_string(const char* str, int slen, sip_t* dest) {
qfits_header* hdr;
sip_t* rtn;
if (slen == 0) {
slen = strlen(str);
}
hdr = qfits_header_read_hdr_string((const unsigned char*)str, slen);
if (!hdr) {
ERROR("Failed to parse a FITS header from the given string");
return NULL;
}
rtn = sip_read_header(hdr, dest);
qfits_header_destroy(hdr);
return rtn;
}
const qfits_header* anqfits_get_header_const(const anqfits_t* qf, int ext) {
assert(ext >= 0 && ext < qf->Nexts);
if (!qf->exts[ext].header) {
off_t start, size;
char* str;
start = anqfits_header_start(qf, ext);
size = anqfits_header_size (qf, ext);
if ((start == -1) || (size == -1)) {
ERROR("failed to get header start + size for file \"%s\" extension %i", qf->filename, ext);
return NULL;
}
str = file_get_contents_offset(qf->filename, (int)start, (int)size);
if (!str) {
ERROR("failed to read \"%s\" extension %i: offset %i size %i\n", qf->filename, ext, (int)start, (int)size);
return NULL;
}
qf->exts[ext].header = qfits_header_read_hdr_string
((unsigned char*)str, (int)size);
}
return qf->exts[ext].header;
}
int wcs_pv2sip(const char* wcsinfn, int ext,
const char* wcsoutfn,
anbool scamp_head_file,
double* xy, int Nxy,
int imageW, int imageH,
anbool forcetan) {
qfits_header* hdr = NULL;
double* radec = NULL;
int rtn = -1;
tan_t tanwcs;
double x,y, px,py;
double xyz[3];
double* xorig = NULL;
double* yorig = NULL;
double* rddist = NULL;
int i, j;
// 1 x y r x2 xy y2 x3 x2y xy2 y3 r3 x4 x3y x2y2 xy3 y4
// x5 x4y x3y2 x2y3 xy4 y5 r5 x6 x5y x4y2, x3y3 x2y4 xy5 y6
// x7 x6y x5y2 x4y3 x3y4 x2y5 xy6 y7 r7
int xp[] = { 0, 1, 0, 0, 2, 1, 0, 3, 2, 1, 0, 0, 4, 3, 2, 1, 0,
5, 4, 3, 2, 1, 5, 0, 6, 5, 4, 3, 2, 1, 0,
7, 6, 5, 4, 3, 2, 1, 0, 0};
int yp[] = { 0, 0, 1, 0, 0, 1, 2, 0, 1, 2, 3, 0, 0, 1, 2, 3, 4,
0, 1, 2, 3, 4, 0, 0, 0, 1, 2, 3, 4, 5, 6,
0, 1, 2, 3, 4, 5, 6, 7, 0};
int rp[] = { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 7};
double xpows[8];
double ypows[8];
double rpows[8];
double pv1[40];
double pv2[40];
double r;
if (scamp_head_file) {
size_t sz = 0;
char* txt;
char* prefix;
int np;
int nt;
unsigned char* txthdr;
sl* lines;
int i;
txt = file_get_contents(wcsinfn, &sz, TRUE);
if (!txt) {
ERROR("Failed to read file %s", wcsinfn);
goto bailout;
}
lines = sl_split(NULL, txt, "\n");
prefix =
"SIMPLE = T / Standard FITS file "
"BITPIX = 8 / ASCII or bytes array "
"NAXIS = 0 / Minimal header "
"EXTEND = T / There may be FITS ext "
"WCSAXES = 2 / ";
np = strlen(prefix);
nt = np + FITS_LINESZ * sl_size(lines);
txthdr = malloc(nt);
memset(txthdr, ' ', np + FITS_LINESZ * sl_size(lines));
memcpy(txthdr, prefix, np);
for (i=0; i<sl_size(lines); i++)
memcpy(txthdr + np + i*FITS_LINESZ, sl_get(lines, i), strlen(sl_get(lines, i)));
sl_free2(lines);
hdr = qfits_header_read_hdr_string(txthdr, nt);
free(txthdr);
free(txt);
} else {
char* ct;
hdr = anqfits_get_header2(wcsinfn, ext);
ct = fits_get_dupstring(hdr, "CTYPE1");
if ((ct && streq(ct, "RA---TPV")) || forcetan) {
// http://iraf.noao.edu/projects/ccdmosaic/tpv.html
logmsg("Replacing CTYPE1 = %s header with RA---TAN\n", ct);
fits_update_value(hdr, "CTYPE1", "RA---TAN");
}
ct = fits_get_dupstring(hdr, "CTYPE2");
if ((ct && streq(ct, "DEC--TPV")) || forcetan) {
logmsg("Replacing CTYPE2 = %s header with DEC--TAN\n", ct);
fits_update_value(hdr, "CTYPE2", "DEC--TAN");
}
}
if (!hdr) {
ERROR("Failed to read header: file %s, ext %i\n", wcsinfn, ext);
goto bailout;
}
tan_read_header(hdr, &tanwcs);
for (i=0; i<sizeof(pv1)/sizeof(double); i++) {
char key[10];
sprintf(key, "PV1_%i", i);
pv1[i] = qfits_header_getdouble(hdr, key, 0.0);
sprintf(key, "PV2_%i", i);
pv2[i] = qfits_header_getdouble(hdr, key, 0.0);
}
xorig = malloc(Nxy * sizeof(double));
yorig = malloc(Nxy * sizeof(double));
rddist = malloc(2 * Nxy * sizeof(double));
for (j=0; j<Nxy; j++) {
xorig[j] = xy[2*j+0];
yorig[j] = xy[2*j+1];
tan_pixelxy2iwc(&tanwcs, xorig[j], yorig[j], &x, &y);
r = sqrt(x*x + y*y);
xpows[0] = ypows[0] = rpows[0] = 1.0;
for (i=1; i<sizeof(xpows)/sizeof(double); i++) {
xpows[i] = xpows[i-1]*x;
ypows[i] = ypows[i-1]*y;
rpows[i] = rpows[i-1]*r;
}
px = py = 0;
for (i=0; i<sizeof(xp)/sizeof(int); i++) {
px += pv1[i] * xpows[xp[i]] * ypows[yp[i]] * rpows[rp[i]];
py += pv2[i] * ypows[xp[i]] * xpows[yp[i]] * rpows[rp[i]];
}
tan_iwc2xyzarr(&tanwcs, px, py, xyz);
xyzarr2radecdeg(xyz, rddist+2*j, rddist+2*j+1);
}
//
{
starxy_t sxy;
tweak_t* t;
il* imgi;
il* refi;
int sip_order = 5;
int sip_inv_order = 5;
sxy.N = Nxy;
sxy.x = xorig;
sxy.y = yorig;
imgi = il_new(256);
refi = il_new(256);
for (i=0; i<Nxy; i++) {
il_append(imgi, i);
il_append(refi, i);
}
t = tweak_new();
t->sip->a_order = t->sip->b_order = sip_order;
t->sip->ap_order = t->sip->bp_order = sip_inv_order;
tweak_push_wcs_tan(t, &tanwcs);
tweak_push_ref_ad_array(t, rddist, Nxy);
tweak_push_image_xy(t, &sxy);
tweak_push_correspondence_indices(t, imgi, refi, NULL, NULL);
tweak_go_to(t, TWEAK_HAS_LINEAR_CD);
if (imageW)
t->sip->wcstan.imagew = imageW;
if (imageH)
t->sip->wcstan.imageh = imageH;
sip_write_to_file(t->sip, wcsoutfn);
tweak_free(t);
}
rtn = 0;
bailout:
free(xorig);
free(yorig);
free(rddist);
qfits_header_destroy(hdr);
free(radec);
return rtn;
}
/**
Evaluates the given TAN-TPV WCS header on a grid of points,
fitting a SIP distortion solution to it.
The grid can be specified by either:
double* xy, int Nxy
double stepsize=100, double xlo=0, double xhi=0, double ylo=0, double yhi=0
xlo and xhi, if both 0, default to 1. and the WCS width
ylo and yhi, if both 0, default to 1. and the WCS height
The number of steps is chosen to be the closest step size to split the range
xlo to xhi into an integer number of steps.
imageW and imageH, if non-zero, override the image width read from the WCS,
and ALSO the WCS width/height mentioned above.
*/
int wcs_pv2sip(const char* wcsinfn, int ext,
const char* wcsoutfn,
anbool scamp_head_file,
double* xy, int Nxy,
double stepsize,
double xlo, double xhi,
double ylo, double yhi,
int imageW, int imageH,
int order,
anbool forcetan,
int doshift) {
qfits_header* hdr = NULL;
sip_t* sip = NULL;
int rtn = -1;
if (scamp_head_file) {
size_t sz = 0;
char* txt;
char* prefix;
int np;
int nt;
unsigned char* txthdr;
sl* lines;
int i;
txt = file_get_contents(wcsinfn, &sz, TRUE);
if (!txt) {
ERROR("Failed to read file %s", wcsinfn);
goto bailout;
}
lines = sl_split(NULL, txt, "\n");
prefix =
"SIMPLE = T / Standard FITS file "
"BITPIX = 8 / ASCII or bytes array "
"NAXIS = 0 / Minimal header "
"EXTEND = T / There may be FITS ext "
"WCSAXES = 2 / ";
np = strlen(prefix);
nt = np + FITS_LINESZ * sl_size(lines);
txthdr = malloc(nt);
memset(txthdr, ' ', np + FITS_LINESZ * sl_size(lines));
memcpy(txthdr, prefix, np);
for (i=0; i<sl_size(lines); i++)
memcpy(txthdr + np + i*FITS_LINESZ, sl_get(lines, i), strlen(sl_get(lines, i)));
sl_free2(lines);
hdr = qfits_header_read_hdr_string(txthdr, nt);
free(txthdr);
free(txt);
} else {
hdr = anqfits_get_header2(wcsinfn, ext);
}
if (!hdr) {
ERROR("Failed to read header: file %s, ext %i\n", wcsinfn, ext);
goto bailout;
}
sip = wcs_pv2sip_header(hdr, xy, Nxy, stepsize, xlo, xhi, ylo, yhi,
imageW, imageH, order, forcetan, doshift);
if (!sip) {
goto bailout;
}
sip_write_to_file(sip, wcsoutfn);
rtn = 0;
bailout:
qfits_header_destroy(hdr);
return rtn;
}
