diff --git a/django/contrib/gis/gdal/raster/source.py b/django/contrib/gis/gdal/raster/source.py
index 904d2f783a..432a1eb7f4 100644
--- a/django/contrib/gis/gdal/raster/source.py
+++ b/django/contrib/gis/gdal/raster/source.py
@@ -108,9 +108,22 @@ class GDALRaster(GDALBase):
# Set band data if provided
for i, band_input in enumerate(ds_input.get('bands', [])):
band = self.bands[i]
- band.data(band_input['data'])
if 'nodata_value' in band_input:
band.nodata_value = band_input['nodata_value']
+ # Instantiate band filled with nodata values if only
+ # partial input data has been provided.
+ if band.nodata_value is not None and (
+ 'data' not in band_input or
+ 'size' in band_input or
+ 'shape' in band_input):
+ band.data(data=(band.nodata_value,), shape=(1, 1))
+ # Set band data values from input.
+ band.data(
+ data=band_input.get('data'),
+ size=band_input.get('size'),
+ shape=band_input.get('shape'),
+ offset=band_input.get('offset'),
+ )
# Set SRID
self.srs = ds_input.get('srid')
@@ -339,16 +352,12 @@ class GDALRaster(GDALBase):
if 'datatype' not in ds_input:
ds_input['datatype'] = self.bands[0].datatype()
- # Set the number of bands
- ds_input['nr_of_bands'] = len(self.bands)
+ # Instantiate raster bands filled with nodata values.
+ ds_input['bands'] = [{'nodata_value': bnd.nodata_value} for bnd in self.bands]
# Create target raster
target = GDALRaster(ds_input, write=True)
- # Copy nodata values to warped raster
- for index, band in enumerate(self.bands):
- target.bands[index].nodata_value = band.nodata_value
-
# Select resampling algorithm
algorithm = GDAL_RESAMPLE_ALGORITHMS[resampling]
diff --git a/docs/ref/contrib/gis/gdal.txt b/docs/ref/contrib/gis/gdal.txt
index 9bd2df8dad..3f9219dc0d 100644
--- a/docs/ref/contrib/gis/gdal.txt
+++ b/docs/ref/contrib/gis/gdal.txt
@@ -1117,16 +1117,39 @@ blue.
>>> rst = GDALRaster('/path/to/your/raster.tif', write=False)
>>> rst.name
'/path/to/your/raster.tif'
- >>> rst.width, rst.height # This file has 163 x 174 pixels
+ >>> rst.width, rst.height # This file has 163 x 174 pixels
(163, 174)
- >>> rst = GDALRaster({'srid': 4326, 'width': 1, 'height': 2, 'datatype': 1
- ... 'bands': [{'data': [0, 1]}]}) # Creates in-memory raster
+ >>> rst = GDALRaster({ # Creates an in-memory raster
+ ... 'srid': 4326,
+ ... 'width': 4,
+ ... 'height': 4,
+ ... 'datatype': 1,
+ ... 'bands': [{
+ ... 'data': (2, 3),
+ ... 'offset': (1, 1),
+ ... 'size': (2, 2),
+ ... 'shape': (2, 1),
+ ... 'nodata_value': 5,
+ ... }]
+ ... })
>>> rst.srs.srid
4326
>>> rst.width, rst.height
- (1, 2)
+ (4, 4)
>>> rst.bands[0].data()
- array([[0, 1]], dtype=int8)
+ array([[5, 5, 5, 5],
+ [5, 2, 3, 5],
+ [5, 2, 3, 5],
+ [5, 5, 5, 5]], dtype=uint8)
+
+ .. versionchanged:: 1.11
+
+ Added the ability to pass the ``size``, ``shape``, and ``offset``
+ parameters when creating :class:`GDALRaster` objects. The parameters
+ can be passed through the ``ds_input`` dictionary. This allows to
+ finely control initial pixel values. The functionality is similar to
+ the :meth:`GDALBand.data()<django.contrib.gis.gdal.GDALBand.data>`
+ method.
.. attribute:: name
diff --git a/docs/releases/1.11.txt b/docs/releases/1.11.txt
index a612cb0e12..77a1c3ea12 100644
--- a/docs/releases/1.11.txt
+++ b/docs/releases/1.11.txt
@@ -148,6 +148,9 @@ Minor features
* PostGIS migrations can now change field dimensions.
+* Added the ability to pass the `size`, `shape`, and `offset` parameter when
+ creating :class:`~django.contrib.gis.gdal.GDALRaster` objects.
+
:mod:`django.contrib.messages`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/tests/gis_tests/gdal_tests/test_raster.py b/tests/gis_tests/gdal_tests/test_raster.py
index 53f1bf985a..bddb3c8826 100644
--- a/tests/gis_tests/gdal_tests/test_raster.py
+++ b/tests/gis_tests/gdal_tests/test_raster.py
@@ -190,6 +190,64 @@ class GDALRasterTests(unittest.TestCase):
else:
self.assertEqual(restored_raster.bands[0].data(), self.rs.bands[0].data())
+ def test_offset_size_and_shape_on_raster_creation(self):
+ rast = GDALRaster({
+ 'datatype': 1,
+ 'width': 4,
+ 'height': 4,
+ 'srid': 4326,
+ 'bands': [{
+ 'data': (1,),
+ 'offset': (1, 1),
+ 'size': (2, 2),
+ 'shape': (1, 1),
+ 'nodata_value': 2,
+ }],
+ })
+ # Get array from raster.
+ result = rast.bands[0].data()
+ if numpy:
+ result = result.flatten().tolist()
+ # Band data is equal to nodata value except on input block of ones.
+ self.assertEqual(
+ result,
+ [2, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2]
+ )
+
+ def test_set_nodata_value_on_raster_creation(self):
+ # Create raster filled with nodata values.
+ rast = GDALRaster({
+ 'datatype': 1,
+ 'width': 2,
+ 'height': 2,
+ 'srid': 4326,
+ 'bands': [{'nodata_value': 23}],
+ })
+ # Get array from raster.
+ result = rast.bands[0].data()
+ if numpy:
+ result = result.flatten().tolist()
+ # All band data is equal to nodata value.
+ self.assertEqual(result, [23, ] * 4)
+
+ def test_set_nodata_none_on_raster_creation(self):
+ if GDAL_VERSION < (2, 1):
+ self.skipTest("GDAL >= 2.1 is required for this test.")
+ # Create raster without data and without nodata value.
+ rast = GDALRaster({
+ 'datatype': 1,
+ 'width': 2,
+ 'height': 2,
+ 'srid': 4326,
+ 'bands': [{'nodata_value': None}],
+ })
+ # Get array from raster.
+ result = rast.bands[0].data()
+ if numpy:
+ result = result.flatten().tolist()
+ # Band data is equal to zero becaues no nodata value has been specified.
+ self.assertEqual(result, [0] * 4)
+
def test_raster_warp(self):
# Create in memory raster
source = GDALRaster({
@@ -246,6 +304,29 @@ class GDALRasterTests(unittest.TestCase):
12.0, 13.0, 14.0, 15.0]
)
+ def test_raster_warp_nodata_zone(self):
+ # Create in memory raster.
+ source = GDALRaster({
+ 'datatype': 1,
+ 'driver': 'MEM',
+ 'width': 4,
+ 'height': 4,
+ 'srid': 3086,
+ 'origin': (500000, 400000),
+ 'scale': (100, -100),
+ 'skew': (0, 0),
+ 'bands': [{
+ 'data': range(16),
+ 'nodata_value': 23,
+ }],
+ })
+ # Warp raster onto a location that does not cover any pixels of the original.
+ result = source.warp({'origin': (200000, 200000)}).bands[0].data()
+ if numpy:
+ result = result.flatten().tolist()
+ # The result is an empty raster filled with the correct nodata value.
+ self.assertEqual(result, [23] * 16)
+
def test_raster_transform(self):
if GDAL_VERSION < (1, 8, 1):
self.skipTest("GDAL >= 1.8.1 is required for this test")