cuDenseOff*.prep*Geom*: supp. full-reso file w/o .full in the name

+ support full resolution geometry files without ".full" in the filename, such as provided by stripmapStack

+ add --fix-xml option to update the image file path in the xml file, so that IML.loadImage is not called all the time, which could lead to file access issue when multiple processes use the same SLC file

contrib/PyCuAmpcor/examples/cuDenseOffsets.py

@@ -40,6 +40,8 @@ def createParser():
                         help='Reference image')
     parser.add_argument('-s', '--secondary',type=str, dest='secondary', required=True,
                         help='Secondary image')
+    parser.add_argument('--fix-xml','--fix-image-xml', dest='fixImageXml', action='store_true',
+                        help='Fix the image file path in the XML file. Enable this if input files havee been moved.')
 
     parser.add_argument('--op','--outprefix','--output-prefix', type=str, dest='outprefix',
                         default='offset', required=True,
@@ -166,12 +168,13 @@ def estimateOffsetField(reference, secondary, inps=None):
             return 0
 
     # update file path in xml file
-    for fname in [reference, secondary]:
-        fname = os.path.abspath(fname)
-        img = IML.loadImage(fname)[0]
-        img.filename = fname
-        img.setAccessMode('READ')
-        img.renderHdr()
+    if inps.fixImageXml:
+        for fname in [reference, secondary]:
+            fname = os.path.abspath(fname)
+            img = IML.loadImage(fname)[0]
+            img.filename = fname
+            img.setAccessMode('READ')
+            img.renderHdr()
 
     ###Loading the secondary image object
     sim = isceobj.createSlcImage()
@@ -382,14 +385,24 @@ def prepareGeometry(full_dir, out_dir, x_start, y_start, x_step, y_step, num_win
                 x/y_step    - int, output pixel step in column/row direction
                 num_win_x/y - int, number of columns/rows
     """
+    full_dir = os.path.abspath(full_dir)
+    out_dir = os.path.abspath(out_dir)
+
+    # grab the file extension for full resolution file
+    full_exts = ['.rdr.full','.rdr'] if full_dir != out_dir else ['.rdr.full']
+    full_exts = [e for e in full_exts if os.path.isfile(os.path.join(full_dir, '{f}{e}'.format(f=fbases[0], e=e)))]
+    if len(full_exts) == 0:
+        raise ValueError('No full resolution {}.rdr* file found in: {}'.format(fbases[0], full_dir))
+    full_ext = full_exts[0]
+
     print('-'*50)
     print('generate the corresponding multi-looked geometry datasets using gdal ...')
-    in_files = [os.path.join(full_dir, '{}.rdr.full'.format(i)) for i in fbases]
+    # input files
+    in_files = [os.path.join(full_dir, '{f}{e}'.format(f=f, e=full_ext)) for f in fbases]
     in_files = [i for i in in_files if os.path.isfile(i)]
-    if len(in_files) == 0:
-        raise ValueError('No full resolution geometry file found in: {}'.format(full_dir))
-
     fbases = [os.path.basename(i).split('.')[0] for i in in_files]
+
+    # output files
     out_files = [os.path.join(out_dir, '{}.rdr'.format(i)) for i in fbases]
     os.makedirs(out_dir, exist_ok=True)