Round data to nearest integer before converting to 8bit (#250)

* round data to nearest integer before converting to 8bit

* fix tests

* fix tests

terracotta/cache.py

@@ -35,7 +35,7 @@ def __setitem__(self, key: Any,
     def _compress_ma(arr: np.ma.MaskedArray, compression_level: int) -> CompressionTuple:
         compressed_data = zlib.compress(arr.data, compression_level)
         mask_to_int = np.packbits(arr.mask.astype(np.uint8))
-        compressed_mask = zlib.compress(mask_to_int, compression_level)
+        compressed_mask = zlib.compress(mask_to_int.data, compression_level)
         out = (
             compressed_data,
             compressed_mask,

terracotta/drivers/mysql.py

@@ -287,7 +287,7 @@ def create(self, keys: Sequence[str], key_descriptions: Mapping[str, str] = None
             binary_prefix=True, charset='utf8mb4'
         )
 
-        with connection, connection.cursor() as cursor:  # type: ignore
+        with connection, connection.cursor() as cursor:
             cursor.execute(f'CREATE DATABASE {self._db_args.db}')
 
         with self._connect(check=False):

terracotta/image.py

@@ -149,6 +149,7 @@ def contrast_stretch(data: Array,
 def to_uint8(data: Array, lower_bound: Number, upper_bound: Number) -> Array:
     """Re-scale an array to [1, 255] and cast to uint8 (0 is used for transparency)"""
     rescaled = contrast_stretch(data, (lower_bound, upper_bound), (1, 255), clip=True)
+    rescaled = np.rint(rescaled)
     return rescaled.astype(np.uint8)
 
 

tests/handlers/test_colormap.py

@@ -63,3 +63,17 @@ def test_colormap_consistency(use_testdb, testdb, raster_file_xyz,
     for val in values_to_test:
         rgba = cmap[val]
         assert np.all(img_data[tile_data == val] == rgba)
+
+
+@pytest.mark.parametrize('stretch_range', [[0, 0.1], [20000, 30000], [-50000, 50000]])
+def test_colormap_range(stretch_range):
+    """Ensure that all colors from colormap file are present in returned data"""
+    from terracotta.cmaps import get_cmap
+    from terracotta.handlers import colormap
+    cmap_name = 'jet'
+    cmap_in = get_cmap(cmap_name)
+    num_values = cmap_in.shape[0]
+    cmap_out = colormap.colormap(colormap=cmap_name, stretch_range=stretch_range,
+                                 num_values=num_values)
+    cmap_out_arr = np.array([val['rgba'] for val in cmap_out], dtype=cmap_in.dtype)
+    np.testing.assert_array_equal(cmap_in, cmap_out_arr)

tests/test_image.py

@@ -87,7 +87,7 @@ def test_to_uint8():
     data = np.array([-50, 0, 10, 255, 256, 1000])
     np.testing.assert_array_equal(
         image.to_uint8(data, -50, 1000),
-        [1, 13, 15, 74, 75, 255]
+        [1, 13, 16, 75, 75, 255]
     )