Fixed #28288 -- Allowed passing papsz options to GDALRaster initiation.

django/contrib/gis/gdal/raster/source.py

@@ -1,6 +1,6 @@
 import json
 import os
-from ctypes import addressof, byref, c_double, c_void_p
+from ctypes import addressof, byref, c_char_p, c_double, c_void_p
 
 from django.contrib.gis.gdal.driver import Driver
 from django.contrib.gis.gdal.error import GDALException
@@ -92,6 +92,16 @@ def __init__(self, ds_input, write=False):
             if 'srid' not in ds_input:
                 raise GDALException('Specify srid for JSON or dict input.')
 
+            # Create null terminated gdal options array.
+            papsz_options = []
+            for key, val in ds_input.get('papsz_options', {}).items():
+                option = '{0}={1}'.format(key, val)
+                papsz_options.append(option.upper().encode())
+            papsz_options.append(None)
+
+            # Convert papszlist to ctypes array.
+            papsz_options = (c_char_p * len(papsz_options))(*papsz_options)
+
             # Create GDAL Raster
             self._ptr = capi.create_ds(
                 driver._ptr,
@@ -100,7 +110,7 @@ def __init__(self, ds_input, write=False):
                 ds_input['height'],
                 ds_input.get('nr_of_bands', len(ds_input.get('bands', []))),
                 ds_input.get('datatype', 6),
-                None
+                byref(papsz_options),
             )
 
             # Set band data if provided
@@ -135,6 +145,7 @@ def __init__(self, ds_input, write=False):
 
             if 'skew' in ds_input:
                 self.skew.x, self.skew.y = ds_input['skew']
+
         elif isinstance(ds_input, c_void_p):
             # Instantiate the object using an existing pointer to a gdal raster.
             self._ptr = ds_input

docs/ref/contrib/gis/gdal.txt

@@ -1619,21 +1619,22 @@ the others are described below.
 The following table describes all keys that can be set in the ``ds_input``
 dictionary.
 
-=============== ======== ==================================================
-Key             Default  Usage
-=============== ======== ==================================================
-``srid``        required Mapped to the :attr:`~GDALRaster.srid` attribute
-``width``       required Mapped to the :attr:`~GDALRaster.width` attribute
-``height``      required Mapped to the :attr:`~GDALRaster.height` attribute
-``driver``      ``MEM``  Mapped to the :attr:`~GDALRaster.driver` attribute
-``name``        ``''``   See below
-``origin``      ``0``    Mapped to the :attr:`~GDALRaster.origin` attribute
-``scale``       ``0``    Mapped to the :attr:`~GDALRaster.scale` attribute
-``skew``        ``0``    Mapped to the :attr:`~GDALRaster.width` attribute
-``bands``       ``[]``   See below
-``nr_of_bands`` ``0``    See below
-``datatype``    ``6``    See below
-=============== ======== ==================================================
+================= ======== ==================================================
+Key               Default  Usage
+================= ======== ==================================================
+``srid``          required Mapped to the :attr:`~GDALRaster.srid` attribute
+``width``         required Mapped to the :attr:`~GDALRaster.width` attribute
+``height``        required Mapped to the :attr:`~GDALRaster.height` attribute
+``driver``        ``MEM``  Mapped to the :attr:`~GDALRaster.driver` attribute
+``name``          ``''``   See below
+``origin``        ``0``    Mapped to the :attr:`~GDALRaster.origin` attribute
+``scale``         ``0``    Mapped to the :attr:`~GDALRaster.scale` attribute
+``skew``          ``0``    Mapped to the :attr:`~GDALRaster.width` attribute
+``bands``         ``[]``   See below
+``nr_of_bands``   ``0``    See below
+``datatype``      ``6``    See below
+``papsz_options`` ``{}``   See below
+================= ======== ==================================================
 
 .. object:: name
 
@@ -1673,6 +1674,34 @@ Key             Default  Usage
     raster bands values are instantiated as an array of zeros and the "no
     data" value is set to ``None``.
 
+.. object:: papsz_options
+
+    .. versionadded:: 2.0
+
+    A dictionary with raster creation options. The key-value pairs of the
+    dictionary are passed as options to the driver on creation of the raster.
+    The values in the options dictionary are not case sensitive, they are
+    automatically converted into the right string format upon creation.
+
+    GDAL allows each driver to have its own specific creation options. These
+    options are known as "papsz options" and are passed to GDAL as an array
+    of ``name=value`` strings. The documentation of each driver specifies what
+    options it accepts.
+
+    The following example is an options set for the `GTiff driver`__. With
+    these options, a compressed raster with a signed byte pixel type and a
+    tile block size of 23 by 23 would be created::
+
+        papsz_options = {
+            'compress': 'packbits',
+            'pixeltype': 'signedbyte',
+            'blockxsize': 23,
+            'blockysize': 23,
+        }
+
+
+__ http://www.gdal.org/frmt_gtiff.html
+
 The ``band_input`` dictionary
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/releases/2.0.txt

@@ -83,6 +83,9 @@ Minor features
   :attr:`~django.contrib.gis.gdal.GDALRaster.info`, and
   :attr:`~django.contrib.gis.gdal.GDALBand.metadata` attributes.
 
+* Allowed passing driver specific creation options to
+  :class:`~django.contrib.gis.gdal.GDALRaster` objects.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tests/gis_tests/gdal_tests/test_raster.py

@@ -310,6 +310,48 @@ def test_raster_info_accessor(self):
         info_ref = [line.strip() for line in gdalinfo.split('\n') if line.strip() != '']
         self.assertEqual(info_dyn, info_ref)
 
+    def test_compressed_file_based_raster_creation(self):
+        # Prepare tempfile
+        rstfile = tempfile.NamedTemporaryFile(suffix='.tif')
+
+        # Make a compressed copy of an existing raster.
+        compressed = self.rs.warp({'papsz_options': {'compress': 'packbits'}, 'name': rstfile.name})
+
+        # Check pysically if compression worked.
+        self.assertTrue(
+            os.path.getsize(compressed.name) < os.path.getsize(self.rs.name)
+        )
+
+        # Create file-based raster with options from scratch.
+        compressed = GDALRaster({
+            'datatype': 1,
+            'driver': 'tif',
+            'name': rstfile.name,
+            'width': 40,
+            'height': 40,
+            'srid': 3086,
+            'origin': (500000, 400000),
+            'scale': (100, -100),
+            'skew': (0, 0),
+            'bands': [{
+                'data': range(40 ^ 2),
+                'nodata_value': 255,
+            }],
+            'papsz_options': {
+                'compress': 'packbits',
+                'pixeltype': 'signedbyte',
+                'blockxsize': 23,
+                'blockysize': 23,
+            }
+        })
+
+        # Check if options used on creation and stored in metadata. Re-opening
+        # the raster ensures that all metadata has been written to file.
+        compressed = GDALRaster(compressed.name)
+        self.assertEqual(compressed.metadata['IMAGE_STRUCTURE']['COMPRESSION'], 'PACKBITS')
+        self.assertEqual(compressed.bands[0].metadata['IMAGE_STRUCTURE']['PIXELTYPE'], 'SIGNEDBYTE')
+        self.assertIn('Block=40x23', compressed.info)
+
     def test_raster_warp(self):
         # Create in memory raster
         source = GDALRaster({