fitsfile* create_fits_file(const char* filename, int precision,
int width, int height, int num_times, int num_channels,
double centre_deg[2], double fov_deg[2], double start_time_mjd,
double delta_time_sec, double start_freq_hz, double delta_freq_hz,
int* status)
{
long naxes[4];
double delta;
fitsfile* f = 0;
FILE* t = 0;
if (*status) return 0;
/* Create a new FITS file and write the image headers. */
t = fopen(filename, "rb");
if (t)
{
fclose(t);
remove(filename);
}
naxes[0] = width;
naxes[1] = height;
naxes[2] = num_channels;
naxes[3] = num_times;
fits_create_file(&f, filename, status);
fits_create_img(f, (precision == OSKAR_DOUBLE ? DOUBLE_IMG : FLOAT_IMG),
4, naxes, status);
fits_write_date(f, status);
/* Write axis headers. */
delta = oskar_convert_fov_to_cellsize(fov_deg[0] * M_PI/180, width) * 180/M_PI;
write_axis_header(f, 1, "RA---SIN", "Right Ascension",
centre_deg[0], -delta, width / 2 + 1, 0.0, status);
delta = oskar_convert_fov_to_cellsize(fov_deg[1] * M_PI/180, height) * 180/M_PI;
write_axis_header(f, 2, "DEC--SIN", "Declination",
centre_deg[1], delta, height / 2 + 1, 0.0, status);
write_axis_header(f, 3, "FREQ", "Frequency",
start_freq_hz, delta_freq_hz, 1.0, 0.0, status);
write_axis_header(f, 4, "UTC", "Time",
start_time_mjd, delta_time_sec, 1.0, 0.0, status);
/* Write other headers. */
fits_write_key_str(f, "BUNIT", "JY/BEAM", "Brightness units", status);
fits_write_key_str(f, "TIMESYS", "UTC", NULL, status);
fits_write_key_str(f, "TIMEUNIT", "s", "Time axis units", status);
fits_write_key_dbl(f, "MJD-OBS", start_time_mjd, 10, "Start time", status);
fits_write_key_dbl(f, "OBSRA", centre_deg[0], 10, "RA", status);
fits_write_key_dbl(f, "OBSDEC", centre_deg[1], 10, "DEC", status);
/*fits_flush_file(f, status);*/
return f;
}
static void write_axis(fitsfile* fptr, int axis_id, const char* ctype,
const char* ctype_comment, double crval, double cdelt, double crpix,
int* status)
{
char key[FLEN_KEYWORD], value[FLEN_VALUE], comment[FLEN_COMMENT];
int decimals = 10;
strncpy(comment, ctype_comment, FLEN_COMMENT-1);
strncpy(value, ctype, FLEN_VALUE-1);
fits_make_keyn("CTYPE", axis_id, key, status);
fits_write_key_str(fptr, key, value, comment, status);
fits_make_keyn("CRVAL", axis_id, key, status);
fits_write_key_dbl(fptr, key, crval, decimals, NULL, status);
fits_make_keyn("CDELT", axis_id, key, status);
fits_write_key_dbl(fptr, key, cdelt, decimals, NULL, status);
fits_make_keyn("CRPIX", axis_id, key, status);
fits_write_key_dbl(fptr, key, crpix, decimals, NULL, status);
fits_make_keyn("CROTA", axis_id, key, status);
fits_write_key_dbl(fptr, key, 0.0, decimals, NULL, status);
}
static fitsfile* create_fits_file(const char* filename, int precision,
int width, int height, int num_times, int num_channels,
double centre_deg[2], double fov_deg[2], double start_time_mjd,
double delta_time_sec, double start_freq_hz, double delta_freq_hz,
int horizon_mode, const char* settings_log, size_t settings_log_length,
int* status)
{
int imagetype;
long naxes[4], naxes_dummy[4] = {1l, 1l, 1l, 1l};
double delta;
const double deg2rad = M_PI / 180.0;
const double rad2deg = 180.0 / M_PI;
fitsfile* f = 0;
const char* line;
size_t length;
if (*status) return 0;
/* Create a new FITS file and write the image headers. */
if (oskar_file_exists(filename)) remove(filename);
imagetype = (precision == OSKAR_DOUBLE ? DOUBLE_IMG : FLOAT_IMG);
naxes[0] = width;
naxes[1] = height;
naxes[2] = num_channels;
naxes[3] = num_times;
fits_create_file(&f, filename, status);
fits_create_img(f, imagetype, 4, naxes_dummy, status);
fits_write_date(f, status);
fits_write_key_str(f, "TELESCOP", "OSKAR " OSKAR_VERSION_STR, 0, status);
/* Write axis headers. */
if (horizon_mode)
{
delta = oskar_convert_fov_to_cellsize(M_PI, width);
write_axis(f, 1, "-----SIN", "Azimuthal angle",
0.0, -delta * rad2deg, (width + 1) / 2.0, status);
delta = oskar_convert_fov_to_cellsize(M_PI, height);
write_axis(f, 2, "-----SIN", "Elevation",
90.0, delta * rad2deg, (height + 1) / 2.0, status);
}
else
{
delta = oskar_convert_fov_to_cellsize(fov_deg[0] * deg2rad, width);
write_axis(f, 1, "RA---SIN", "Right Ascension",
centre_deg[0], -delta * rad2deg, (width + 1) / 2.0, status);
delta = oskar_convert_fov_to_cellsize(fov_deg[1] * deg2rad, height);
write_axis(f, 2, "DEC--SIN", "Declination",
centre_deg[1], delta * rad2deg, (height + 1) / 2.0, status);
}
write_axis(f, 3, "FREQ", "Frequency",
start_freq_hz, delta_freq_hz, 1.0, status);
write_axis(f, 4, "UTC", "Time",
start_time_mjd * 86400.0, delta_time_sec, 1.0, status);
/* Write other headers. */
fits_write_key_str(f, "TIMESYS", "UTC", NULL, status);
fits_write_key_str(f, "TIMEUNIT", "s", "Time axis units", status);
fits_write_key_dbl(f, "MJD-OBS", start_time_mjd, 10, "Start time", status);
if (!horizon_mode)
{
fits_write_key_dbl(f, "OBSRA", centre_deg[0], 10, "RA", status);
fits_write_key_dbl(f, "OBSDEC", centre_deg[1], 10, "DEC", status);
}
/* Write the settings log up to this point as HISTORY comments. */
line = settings_log;
length = settings_log_length;
for (; settings_log_length > 0;)
{
const char* eol;
fits_write_history(f, line, status);
eol = (const char*) memchr(line, '\0', length);
if (!eol) break;
eol += 1;
length -= (eol - line);
line = eol;
}
/* Update header keywords with the correct axis lengths.
* Needs to be done here because CFITSIO doesn't let us write only the
* file header with the correct axis lengths to start with. This trick
* allows us to create a small dummy image block to write only the headers,
* and not waste effort moving a huge block of zeros within the file. */
fits_update_key_lng(f, "NAXIS1", naxes[0], 0, status);
fits_update_key_lng(f, "NAXIS2", naxes[1], 0, status);
fits_update_key_lng(f, "NAXIS3", naxes[2], 0, status);
fits_update_key_lng(f, "NAXIS4", naxes[3], 0, status);
return f;
}
/// Saves the current image in the OpenCL memory buffer to the specified FITS file
/// If the OpenCL memory has not been initialzed, this function immediately returns
void CLibOI::ExportImage(string filename)
{
if(mImage_cl == NULL)
return;
// TODO: Adapt for multi-spectral images
Normalize();
// Create a storage buffer for the image and copoy the image to it:
valarray<float> image(mImageWidth * mImageHeight * mImageDepth);
ExportImage(&image[0], mImageWidth, mImageHeight, mImageDepth);
// write out the FITS file:
fitsfile *fptr;
int status = 0;
long fpixel = 1, naxis = 2, nelements;
long naxes[2];
/*Initialise storage*/
naxes[0] = (long) mImageWidth;
naxes[1] = (long) mImageHeight;
nelements = mImageWidth * mImageWidth;
/*Create new file*/
if (status == 0)
fits_create_file(&fptr, filename.c_str(), &status);
/*Create primary array image*/
if (status == 0)
fits_create_img(fptr, FLOAT_IMG, naxis, naxes, &status);
double RPMAS = (M_PI / 180.0) / 3600000.0;
double image_scale_rad = mImageScale * RPMAS;
// Write keywords to get WCS to work //
fits_write_key_dbl(fptr, "CDELT1", -image_scale_rad, 3, "Radians per pixel", &status);
fits_write_key_dbl(fptr, "CDELT2", image_scale_rad, 3, "Radians per pixel", &status);
fits_write_key_dbl(fptr, "CRVAL1", 0.0, 3, "X-coordinate of reference pixel", &status);
fits_write_key_dbl(fptr, "CRVAL2", 0.0, 3, "Y-coordinate of reference pixel", &status);
fits_write_key_lng(fptr, "CRPIX1", naxes[0]/2, "reference pixel in X", &status);
fits_write_key_lng(fptr, "CRPIX2", naxes[1]/2, "reference pixel in Y", &status);
fits_write_key_str(fptr, "CTYPE1", "RA", "Name of X-coordinate", &status);
fits_write_key_str(fptr, "CTYPE2", "DEC", "Name of Y-coordinate", &status);
fits_write_key_str(fptr, "CUNIT1", "rad", "Unit of X-coordinate", &status);
fits_write_key_str(fptr, "CUNIT2", "rad", "Unit of Y-coordinate", &status);
/*Write a keywords (datafile, target, image scale) */
// if (status == 0)
// fits_update_key(fptr, TSTRING, "DATAFILE", "FakeImage", "Data File Name", &status);
// if (status == 0)
// fits_update_key(fptr, TSTRING, "TARGET", "FakeImage", "Target Name", &status);
// if (status == 0)
// fits_update_key(fptr, TFLOAT, "SCALE", &mImageScale, "Scale (mas/pixel)", &status);
/*Write image*/
if (status == 0)
fits_write_img(fptr, TFLOAT, fpixel, nelements, &image[0], &status);
/*Close file*/
if (status == 0)
fits_close_file(fptr, &status);
/*Report any errors*/
fits_report_error(stderr, status);
}
int HPXhdr(fitsfile *fptr, struct healpix *hpxdat)
{
char comment[64], cval[16], *ctype1, *ctype2, *descr1, *descr2, *pcode;
int status;
float cos45, crpix1, crpix2, crval1, crval2, lonpole;
double cdelt1, cdelt2;
status = 0;
fits_update_key_log(fptr, "EXTEND", 0,
"No FITS extensions are present", &status);
fits_write_date(fptr, &status);
/* Set pixel transformation parameters. */
if (hpxdat->layout == 0) {
crpix1 = (5 * hpxdat->nside + 1) / 2.0f;
} else {
crpix1 = (4 * hpxdat->nside + 1) / 2.0f;
}
crpix2 = crpix1;
fits_write_key(fptr, TFLOAT, "CRPIX1", &crpix1,
"Coordinate reference pixel", &status);
fits_write_key(fptr, TFLOAT, "CRPIX2", &crpix2,
"Coordinate reference pixel", &status);
cos45 = (float)sqrt(2.0) / 2.0f;
if (hpxdat->layout == 0) {
fits_write_key_flt(fptr, "PC1_1", cos45, -8,
"Transformation matrix element", &status);
fits_write_key_flt(fptr, "PC1_2", cos45, -8,
"Transformation matrix element", &status);
fits_write_key_flt(fptr, "PC2_1", -cos45, -8,
"Transformation matrix element", &status);
fits_write_key_flt(fptr, "PC2_2", cos45, -8,
"Transformation matrix element", &status);
}
cdelt1 = -90.0 / hpxdat->nside / sqrt(2.0);
cdelt2 = -cdelt1;
fits_write_key_dbl(fptr, "CDELT1", cdelt1, -8,
"[deg] Coordinate increment", &status);
fits_write_key_dbl(fptr, "CDELT2", cdelt2, -8,
"[deg] Coordinate increment", &status);
/* Celestial transformation parameters. */
if (hpxdat->layout == 0) {
pcode = "HPX";
} else {
pcode = "XPH";
}
if (hpxdat->crdsys == 'G') {
/* Galactic. */
ctype1 = "GLON";
ctype2 = "GLAT";
descr1 = "Galactic longitude";
descr2 = "Galactic latitude";
} else if (hpxdat->crdsys == 'E') {
/* Ecliptic, who-knows-what. */
ctype1 = "ELON";
ctype2 = "ELAT";
descr1 = "Ecliptic longitude";
descr2 = "Ecliptic latitude";
} else if (hpxdat->crdsys == 'Q') {
/* Equatorial, who-knows-what. */
ctype1 = "RA--";
ctype2 = "DEC-";
descr1 = "Right ascension";
descr2 = "Declination";
} else {
/* Unknown. */
ctype1 = "XLON";
ctype2 = "XLAT";
descr1 = "Longitude";
descr2 = " Latitude";
}
sprintf(cval, "%s-%s", ctype1, pcode);
sprintf(comment, "%s in an %s projection", descr1, pcode);
fits_write_key_str(fptr, "CTYPE1", cval, comment, &status);
sprintf(cval, "%s-%s", ctype2, pcode);
sprintf(comment, "%s in an %s projection", descr2, pcode);
fits_write_key_str(fptr, "CTYPE2", cval, comment, &status);
crval1 = 0.0f + 90.0f * hpxdat->quad;
if (hpxdat->layout == 0) {
crval2 = 0.0f;
} else if (hpxdat->layout == 1) {
crval1 += 180.0f;
crval2 = 90.0f;
} else {
crval1 += 180.0f;
crval2 = -90.0f;
}
if (360.0f < crval1) crval1 -= 360.0f;
sprintf(comment, "[deg] %s at the reference point", descr1);
fits_write_key(fptr, TFLOAT, "CRVAL1", &crval1, comment, &status);
sprintf(comment, "[deg] %s at the reference point", descr2);
fits_write_key(fptr, TFLOAT, "CRVAL2", &crval2, comment, &status);
if (hpxdat->layout) {
lonpole = 180.0f;
sprintf(comment, "[deg] Native longitude of the celestial pole");
fits_write_key(fptr, TFLOAT, "LONPOLE", &lonpole, comment, &status);
}
if (hpxdat->layout == 0) {
fits_write_key_lng(fptr, "PV2_1", (LONGLONG)4,
"HPX H parameter (longitude)", &status);
fits_write_key_lng(fptr, "PV2_2", (LONGLONG)3,
"HPX K parameter (latitude)", &status);
}
/* Commentary. */
fits_write_record(fptr, " ", &status);
if (hpxdat->layout == 0) {
fits_write_comment(fptr,
"Celestial map with FITS-standard HPX coordinate system generated by",
&status);
} else {
fits_write_comment(fptr,
"Celestial map with XPH coordinate system (polar HPX) generated by",
&status);
}
fits_write_comment(fptr,
"'HPXcvt' which reorganises HEALPix data without interpolation as",
&status);
fits_write_comment(fptr,
"described in \"Mapping on the HEALPix grid\" by Mark Calabretta and",
&status);
fits_write_comment(fptr,
"Boud Roukema. See http://www.atnf.csiro.au/people/Mark.Calabretta",
&status);
return status;
}
