Source code for stwcs.wcsutil.convertwcs

from astropy.io import fits
try:
    import stwcs
    from stwcs import wcsutil
except:
    stwcs = None

from stsci.tools import fileutil

OPUS_WCSKEYS = ['OCRVAL1', 'OCRVAL2', 'OCRPIX1', 'OCRPIX2',
                'OCD1_1', 'OCD1_2', 'OCD2_1', 'OCD2_2',
                'OCTYPE1', 'OCTYPE2']


[docs]def archive_prefix_OPUS_WCS(fobj, extname='SCI'): """ Identifies WCS keywords which were generated by OPUS and archived using a prefix of 'O' for all 'SCI' extensions in the file Parameters ---------- fobj : str or `astropy.io.fits.HDUList` Filename or fits object of a file """ if stwcs is None: print('=====================') print('The STWCS package is needed to convert an old-style OPUS WCS to an alternate WCS') print('=====================') raise ImportError closefits = False if isinstance(fobj, str): # A filename was provided as input fobj = fits.open(fobj, mode='update') closefits = True # Define the header ext = ('sci', 1) hdr = fobj[ext].header numextn = fileutil.countExtn(fobj) extlist = [] for e in range(1, numextn + 1): extlist.append(('sci', e)) # Insure that the 'O' alternate WCS is present if 'O' not in wcsutil.wcskeys(hdr): # if not, archive the Primary WCS as the default OPUS WCS wcsutil.archive_wcs(fobj, extlist, wcskey='O', wcsname='OPUS') # find out how many SCI extensions are in the image numextn = fileutil.countExtn(fobj, extname=extname) if numextn == 0: extname = 'PRIMARY' # create HSTWCS object from PRIMARY WCS wcsobj = wcsutil.HSTWCS(fobj, ext=ext, wcskey='O') # get list of WCS keywords wcskeys = list(wcsobj.wcs2header().keys()) # For each SCI extension... for e in range(1, numextn + 1): # Now, look for any WCS keywords with a prefix of 'O' for key in wcskeys: okey = 'O' + key[: 7] hdr = fobj[(extname, e)].header if okey in hdr: # Update alternate WCS keyword with prefix-O OPUS keyword value hdr[key] = hdr[okey] if closefits: fobj.close()
[docs]def create_prefix_OPUS_WCS(fobj, extname='SCI'): """ Creates alternate WCS with a prefix of 'O' for OPUS generated WCS values to work with old MultiDrizzle. Parameters ---------- fobj : str or `astropy.io.fits.HDUList` Filename or fits object of a file Raises ------ IOError: if input FITS object was not opened in 'update' mode """ # List of O-prefix keywords to create owcskeys = OPUS_WCSKEYS closefits = False if isinstance(fobj, str): # A filename was provided as input fobj = fits.open(fobj, mode='update') closefits = True else: # check to make sure this FITS obj has been opened in update mode if fobj.fileinfo(0)['filemode'] != 'update': print('File not opened with "mode=update". Quitting...') raise IOError # check for existance of O-prefix WCS if owcskeys[0] not in fobj['sci', 1].header: # find out how many SCI extensions are in the image numextn = fileutil.countExtn(fobj, extname=extname) if numextn == 0: extname = '' for extn in range(1, numextn + 1): hdr = fobj[(extname, extn)].header for okey in owcskeys: hdr[okey] = hdr[okey[1: ] + 'O'] # Close FITS image if we had to open it... if closefits: fobj.close()