Merge b1d8d6f into 6617ff7

pytroll · Nov 16, 2023 · 16914ef · 16914ef
2 parents 6617ff7 + b1d8d6f
commit 16914ef
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Showing 2 changed files with 12 additions and 8 deletions.
diff --git a/trollimage/tests/test_image.py b/trollimage/tests/test_image.py
@@ -1456,7 +1456,7 @@ def test_gamma(self):
 
     def test_crude_stretch(self):
         """Check crude stretching."""
-        arr = np.arange(75).reshape(5, 5, 3)
+        arr = np.arange(75, dtype=np.float32).reshape(5, 5, 3)
         data = xr.DataArray(arr.copy(), dims=['y', 'x', 'bands'],
                             coords={'bands': ['R', 'G', 'B']})
         img = xrimage.XRImage(data)
@@ -1467,11 +1467,15 @@ def test_crude_stretch(self):
         enhs = img.data.attrs['enhancement_history'][0]
         scale_expected = np.array([0.01388889, 0.01388889, 0.01388889])
         offset_expected = np.array([0., -0.01388889, -0.02777778])
+        assert img.data.dtype == np.float32
         np.testing.assert_allclose(enhs['scale'].values, scale_expected)
         np.testing.assert_allclose(enhs['offset'].values, offset_expected)
-        np.testing.assert_allclose(red, arr[:, :, 0] / 72.)
-        np.testing.assert_allclose(green, (arr[:, :, 1] - 1.) / (73. - 1.))
-        np.testing.assert_allclose(blue, (arr[:, :, 2] - 2.) / (74. - 2.))
+        expected_red = arr[:, :, 0] / 72.
+        np.testing.assert_allclose(red, expected_red.astype(np.float32), rtol=1e-6)
+        expected_green = (arr[:, :, 1] - 1.) / (73. - 1.)
+        np.testing.assert_allclose(green, expected_green.astype(np.float32), rtol=1e-6)
+        expected_blue = (arr[:, :, 2] - 2.) / (74. - 2.)
+        np.testing.assert_allclose(blue, expected_blue.astype(np.float32), rtol=1e-6)
 
         arr = np.arange(75).reshape(5, 5, 3).astype(float)
         data = xr.DataArray(arr.copy(), dims=['y', 'x', 'bands'],
@@ -2325,10 +2329,10 @@ class TestXRImageSaveScaleOffset:
     def setup_method(self) -> None:
         """Set up the test case."""
         from trollimage import xrimage
-        data = xr.DataArray(np.arange(25).reshape(5, 5, 1), dims=[
+        data = xr.DataArray(np.arange(25, dtype=np.float32).reshape(5, 5, 1), dims=[
             'y', 'x', 'bands'], coords={'bands': ['L']})
         self.img = xrimage.XRImage(data)
-        rgb_data = xr.DataArray(np.arange(3 * 25).reshape(5, 5, 3), dims=[
+        rgb_data = xr.DataArray(np.arange(3 * 25, dtype=np.float32).reshape(5, 5, 3), dims=[
             'y', 'x', 'bands'], coords={'bands': ['R', 'G', 'B']})
         self.rgb_img = xrimage.XRImage(rgb_data)
 

diff --git a/trollimage/xrimage.py b/trollimage/xrimage.py
@@ -1081,9 +1081,9 @@ def crude_stretch(self, min_stretch=None, max_stretch=None):
         delta = (max_stretch - min_stretch)
         if isinstance(delta, xr.DataArray):
             # fillna if delta is NaN
-            scale_factor = (1.0 / delta).fillna(0)
+            scale_factor = (1.0 / delta).fillna(0).astype(self.data.dtype)
         else:
-            scale_factor = 1.0 / delta
+            scale_factor = self.data.dtype.type(1.0 / delta)
         attrs = self.data.attrs
         offset = -min_stretch * scale_factor
         self.data *= scale_factor