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Diffstat (limited to 'updatewcs/det2im.py')
| -rw-r--r-- | updatewcs/det2im.py | 200 |
1 files changed, 0 insertions, 200 deletions
diff --git a/updatewcs/det2im.py b/updatewcs/det2im.py deleted file mode 100644 index b59ca17..0000000 --- a/updatewcs/det2im.py +++ /dev/null @@ -1,200 +0,0 @@ -from __future__ import division # confidence high - -import time -import pyfits -from pytools import fileutil -import utils - -import logging -logger = logging.getLogger('stwcs.updatewcs.Det2IM') - -class DET2IMCorr(object): - """ - Stores a small correction to the detector coordinates as a d2imarr - extension in the science file. - - Notes - ----- - For the case of ACS/WFC every 68th column is wider than the rest. - To compensate for this a small correction needs to be applied to the - detector coordinates. We call this a detector to image transformation. - The so obtained image coordinates are the input to all other distortion - corrections. The correction is originally stored in an external - reference file pointed to by 'D2IMFILE' keyword in the primary header. - This class attaches the correction array as an extension to the science - file with extname = `d2imarr`. - - Other keywords used in this correction are: - - `AXISCORR`: integer (1 or 2) - axis to which the detector to image - correction is applied - - `D2IMEXT`: string = name of reference file which was used to create - the lookup table extension - - `D2IMERR`: float, optional - maximum value of the correction - - """ - def updateWCS(cls, fobj): - """ - Parameters - ---------- - fobj: pyfits object - Science file, for which a detector to image correction - is available - - Notes - ----- - Uses the file pointed to in the primary header keyword 'D2IMFILE' - to create an extension with a detector to image correction. - """ - logger.info("\n\tStarting Det2IM Correction: %s" % time.asctime()) - try: - assert isinstance(fobj, pyfits.HDUList) - except AssertionError: - logger.exception('\n\tInput must be a pyfits.HDUList object') - raise - - d2imfile = fileutil.osfn(fobj[0].header['D2IMFILE']) - axiscorr = cls.getAxisCorr(d2imfile) - d2imerr = pyfits.getdata(d2imfile, ext=1).max() - if axiscorr == None: - new_kw = {} - else: - new_kw = {'D2IMEXT': d2imfile, 'AXISCORR': axiscorr, 'D2IMERR': d2imerr} - cls.applyDet2ImCorr(fobj,axiscorr) - cls.updatehdr(fobj, new_kw) - - updateWCS = classmethod(updateWCS) - - def getAxisCorr(cls, refname): - try: - direction = pyfits.getval(refname, ext=1, key='EXTNAME') - if direction == 'DX': return 1 - elif direction == 'DY': return 2 - else: - logger.warning('\n\tDET2IM correction expects the reference file to have \ - an EXTNAME keyword of value "DX" or "DY", EXTNAMe %s detected' % direction) - return None - except KeyError: - logger.exception("\n\tD2IMFILE %s is missing EXTNAME keyword. Unable to determine axis \ - to which to apply the correction." % refname) - direction = None - return direction - getAxisCorr = classmethod(getAxisCorr) - - def applyDet2ImCorr(cls,fobj, axiscorr): - binned = utils.getBinning(fobj) - hdu = cls.createDgeoHDU(fobj, axiscorr, binned) - d2imarr_ind = cls.getD2imIndex(fobj) - if d2imarr_ind: - fobj[d2imarr_ind] = hdu - else: - fobj.append(hdu) - applyDet2ImCorr = classmethod(applyDet2ImCorr) - - def getD2imIndex(cls,fobj): - index = None - for e in range(len(fobj)): - try: - ename = fobj[e].header['EXTNAME'] - except KeyError: - continue - if ename == 'D2IMARR': - index = e - return index - getD2imIndex = classmethod(getD2imIndex) - - def createDgeoHDU(cls, fobj, axiscorr, binned=1): - d2imfile = fileutil.osfn(fobj[0].header['D2IMFILE']) - d2im_data = pyfits.getdata(d2imfile, ext=1) - sci_hdr = fobj['sci',1].header - d2im_hdr = cls.createDet2ImHdr(fobj, binned) - hdu = pyfits.ImageHDU(header=d2im_hdr, data=d2im_data) - - return hdu - - createDgeoHDU = classmethod(createDgeoHDU) - - def createDet2ImHdr(cls, fobj, binned=1): - """ - Creates a header for the D2IMARR extension based on the - reference file recorded in D2IMFILE keyword in the primary header. - fobj - the science file - - """ - d2imfile = fileutil.osfn(fobj[0].header['D2IMFILE']) - axiscorr = cls.getAxisCorr(d2imfile) - sci_hdr = fobj[1].header - data_shape = pyfits.getdata(d2imfile, ext=1).shape - naxis = pyfits.getval(d2imfile, ext=1, key='NAXIS') - - kw = { 'NAXIS': 'Size of the axis', - 'CRPIX': 'Coordinate system reference pixel', - 'CRVAL': 'Coordinate system value at reference pixel', - 'CDELT': 'Coordinate increment along axis'} - - kw_comm1 = {} - kw_val1 = {} - for key in kw.keys(): - for i in range(1, naxis+1): - si = str(i) - kw_comm1[key+si] = kw[key] - - for i in range(1, naxis+1): - si = str(i) - kw_val1['NAXIS'+si] = data_shape[i-1] - kw_val1['CRPIX'+si] = data_shape[i-1]/2. - kw_val1['CDELT'+si] = 1./binned - kw_val1['CRVAL'+si] = (sci_hdr.get('NAXIS'+si, 1)/2. + \ - sci_hdr.get('LTV'+si, 0.)) / binned - - - kw_comm0 = {'XTENSION': 'Image extension', - 'BITPIX': 'IEEE floating point', - 'NAXIS': 'Number of axes', - 'EXTNAME': 'WCS distortion array', - 'EXTVER': 'Distortion array version number', - 'PCOUNT': 'Special data area of size 0', - 'GCOUNT': 'One data group', - 'AXISCORR': 'Direction in which the det2im correction is applied'} - - kw_val0 = { 'XTENSION': 'IMAGE', - 'BITPIX': -32, - 'NAXIS': naxis, - 'EXTNAME': 'D2IMARR', - 'EXTVER': 1, - 'PCOUNT': 0, - 'GCOUNT': 1, - 'AXISCORR': axiscorr - } - - - cdl = pyfits.CardList() - for key in kw_comm0.keys(): - cdl.append(pyfits.Card(key=key, value=kw_val0[key], comment=kw_comm0[key])) - for key in kw_comm1.keys(): - cdl.append(pyfits.Card(key=key, value=kw_val1[key], comment=kw_comm1[key])) - - hdr = pyfits.Header(cards=cdl) - return hdr - - createDet2ImHdr = classmethod(createDet2ImHdr) - - def updatehdr(cls, fobj, kwdict): - """ - Update extension headers to keep record of the files used for the - detector to image correction. - """ - for ext in fobj: - try: - extname = ext.header['EXTNAME'].lower() - except KeyError: - continue - if extname == 'sci': - for kw in kwdict: - ext.header.update(kw, kwdict[kw]) - else: - continue - updatehdr = classmethod(updatehdr) - |