Fixed #31713 -- Added SpatialReference support to GDALRaster.transform().

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

@@ -425,17 +425,24 @@ class GDALRaster(GDALRasterBase):
 
         return target
 
-    def transform(self, srid, driver=None, name=None, resampling='NearestNeighbour',
+    def transform(self, srs, driver=None, name=None, resampling='NearestNeighbour',
                   max_error=0.0):
         """
-        Return a copy of this raster reprojected into the given SRID.
+        Return a copy of this raster reprojected into the given spatial
+        reference system.
         """
         # Convert the resampling algorithm name into an algorithm id
         algorithm = GDAL_RESAMPLE_ALGORITHMS[resampling]
 
-        # Instantiate target spatial reference system
+        if isinstance(srs, SpatialReference):
-        target_srs = SpatialReference(srid)
+            target_srs = srs
-
+        elif isinstance(srs, (int, str)):
+            target_srs = SpatialReference(srs)
+        else:
+            raise TypeError(
+                'Transform only accepts SpatialReference, string, and integer '
+                'objects.'
+            )
         # Create warped virtual dataset in the target reference system
         target = capi.auto_create_warped_vrt(
             self._ptr, self.srs.wkt.encode(), target_srs.wkt.encode(),
@@ -445,7 +452,7 @@ class GDALRaster(GDALRasterBase):
 
         # Construct the target warp dictionary from the virtual raster
         data = {
-            'srid': srid,
+            'srid': target_srs.srid,
             'width': target.width,
             'height': target.height,
             'origin': [target.origin.x, target.origin.y],

docs/ref/contrib/gis/gdal.txt

@@ -1368,14 +1368,16 @@ blue.
                    [ 19.,  21.,  23.],
                    [ 31.,  33.,  35.]], dtype=float32)
 
-    .. method:: transform(srid, driver=None, name=None, resampling='NearestNeighbour', max_error=0.0)
+    .. method:: transform(srs, driver=None, name=None, resampling='NearestNeighbour', max_error=0.0)
 
-        Returns a transformed version of this raster with the specified SRID.
+        Transforms this raster to a different spatial reference system
+        (``srs``), which may be a :class:`SpatialReference` object, or any
+        other input accepted by :class:`SpatialReference` (including spatial
+        reference WKT and PROJ strings, or an integer SRID).
 
-        This function transforms the current raster into a new spatial reference
+        It calculates the bounds and scale of the current raster in the new
-        system that can be specified with an ``srid``. It calculates the bounds
+        spatial reference system and warps the raster using the
-        and scale of the current raster in the new spatial reference system and
+        :attr:`~GDALRaster.warp` function.
-        warps the raster using the :attr:`~GDALRaster.warp` function.
 
         By default, the driver of the source raster is used and the name of the
         raster is the original name appended with
@@ -1394,10 +1396,15 @@ blue.
             ...     "scale": [100, -100],
             ...     "bands": [{"data": range(36), "nodata_value": 99}]
             ... })
-            >>> target = rst.transform(4326)
+            >>> target_srs = SpatialReference(4326)
+            >>> target = rst.transform(target_srs)
             >>> target.origin
             [-82.98492744885776, 27.601924753080144]
 
+        .. versionchanged:: 3.2
+
+            Support for :class:`SpatialReference` ``srs`` was added
+
     .. attribute:: info
 
         Returns a string with a summary of the raster. This is equivalent to

docs/releases/3.2.txt

@@ -68,7 +68,8 @@ Minor features
 :mod:`django.contrib.gis`
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* ...
+* The :meth:`.GDALRaster.transform` method now supports
+  :class:`~django.contrib.gis.gdal.SpatialReference`.
 
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tests/gis_tests/gdal_tests/test_raster.py

@@ -3,7 +3,7 @@ import shutil
 import struct
 import tempfile
 
-from django.contrib.gis.gdal import GDAL_VERSION, GDALRaster
+from django.contrib.gis.gdal import GDAL_VERSION, GDALRaster, SpatialReference
 from django.contrib.gis.gdal.error import GDALException
 from django.contrib.gis.gdal.raster.band import GDALBand
 from django.contrib.gis.shortcuts import numpy
@@ -471,11 +471,17 @@ class GDALRasterTests(SimpleTestCase):
         self.assertEqual(result, [23] * 16)
 
     def test_raster_transform(self):
-        # Prepare tempfile and nodata value
+        tests = [
+            3086,
+            '3086',
+            SpatialReference(3086),
+        ]
+        for srs in tests:
+            with self.subTest(srs=srs):
+                # Prepare tempfile and nodata value.
                 rstfile = tempfile.NamedTemporaryFile(suffix='.tif')
                 ndv = 99
-
+                # Create in file based raster.
-        # Create in file based raster
                 source = GDALRaster({
                     'datatype': 1,
                     'driver': 'tif',
@@ -493,12 +499,10 @@ class GDALRasterTests(SimpleTestCase):
                     }],
                 })
 
-        # Transform raster into srid 4326.
+                target = source.transform(srs)
-        target = source.transform(3086)
 
-        # Reload data from disk
+                # Reload data from disk.
                 target = GDALRaster(target.name)
-
                 self.assertEqual(target.srs.srid, 3086)
                 self.assertEqual(target.width, 7)
                 self.assertEqual(target.height, 7)
@@ -512,7 +516,6 @@ class GDALRasterTests(SimpleTestCase):
                 result = target.bands[0].data()
                 if numpy:
                     result = result.flatten().tolist()
-
                 # The reprojection of a raster that spans over a large area
                 # skews the data matrix and might introduce nodata values.
                 self.assertEqual(
@@ -525,7 +528,7 @@ class GDALRasterTests(SimpleTestCase):
                         ndv, 10, 11, 16, 22, 23, ndv,
                         ndv, ndv, 15, 21, 22, ndv, ndv,
                         ndv, ndv, 20, ndv, ndv, ndv, ndv,
-            ]
+                    ],
                 )