Redoing the r13221-13223 merge in the actual trunk now. This updates trunk to the setup_refactoring branch (however, coords, pysynphot, and pywcs are still being pulled from the astrolib setup_refactoring branch. Will have to do that separately then update the svn:externals)

git-svn-id: http://svn.stsci.edu/svn/ssb/stsci_python/stsci_python/trunk/stwcs@13225 fe389314-cf27-0410-b35b-8c050e845b92

1 files changed, 200 insertions, 0 deletions

diff --git a/lib/stwcs/updatewcs/det2im.py b/lib/stwcs/updatewcs/det2im.py
new file mode 100644
index 0000000..fe683b4
--- /dev/null
+++ b/lib/stwcs/updatewcs/det2im.py
@@ -0,0 +1,200 @@
+from __future__ import division # confidence high
+
+import time
+import pyfits
+from stsci.tools 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)
+