Make raster_equal accept False mask values of masked arrays (#468)

geoutils/raster/raster.py

@@ -977,7 +977,7 @@ def __setitem__(self, index: Mask | NDArrayBool | Any, assign: NDArrayNum | Numb
             self._data[:, ind] = assign  # type: ignore
         return None
 
-    def raster_equal(self, other: object) -> bool:
+    def raster_equal(self, other: RasterType) -> bool:
         """
         Check if two rasters are equal.
 
@@ -986,12 +986,23 @@ def raster_equal(self, other: object) -> bool:
         - The raster's transform, crs and nodata values.
         """
 
+        # If the mask is just "False", it is equivalent to being equal to an array of False
+        if isinstance(self.data.mask, np.bool_):
+            self_mask = np.zeros(np.shape(self.data), dtype=bool)
+        else:
+            self_mask = self.data.mask
+
+        if isinstance(other.data.mask, np.bool_):
+            other_mask = np.zeros(np.shape(other.data), dtype=bool)
+        else:
+            other_mask = other.data.mask
+
         if not isinstance(other, Raster):  # TODO: Possibly add equals to SatelliteImage?
             raise NotImplementedError("Equality with other object than Raster not supported by raster_equal.")
         return all(
             [
                 np.array_equal(self.data.data, other.data.data, equal_nan=True),
-                np.array_equal(self.data.mask, other.data.mask),
+                np.array_equal(self_mask, other_mask),
                 self.data.fill_value == other.data.fill_value,
                 self.data.dtype == other.data.dtype,
                 self.transform == other.transform,
@@ -3585,14 +3596,14 @@ def __init__(
                 )
                 self._data = self.data[0, :, :]
 
-            # Convert masked array to boolean
-            self._data = self.data.astype(bool)  # type: ignore
+            # Force dtypes
+            self._dtypes = (bool,)
 
             # Fix nodata to None
             self._nodata = None
 
-            # Define in dtypes
-            self._dtypes = (bool,)
+            # Convert masked array to boolean
+            self._data = self.data.astype(bool)  # type: ignore
 
     def __repr__(self) -> str:
         """Convert mask to string representation."""

tests/test_raster.py

@@ -2967,12 +2967,15 @@ def test_reproject(self, mask: gu.Mask) -> None:
         # Test 1: with a classic resampling (bilinear)
 
         # Reproject mask - resample to 100 x 100 grid
+        mask_orig = mask.copy()
         mask_reproj = mask.reproject(grid_size=(100, 100), force_source_nodata=2)
 
         # Check instance is respected
         assert isinstance(mask_reproj, gu.Mask)
         # Check the dtype of the original mask was properly reconverted
         assert mask.data.dtype == bool
+        # Check the original mask was not modified during reprojection
+        assert mask_orig.raster_equal(mask)
 
         # Check inplace behaviour works
         mask_tmp = mask.copy()
@@ -2998,6 +3001,8 @@ def test_reproject(self, mask: gu.Mask) -> None:
     @pytest.mark.parametrize("mask", [mask_landsat_b4, mask_aster_dem, mask_everest])  # type: ignore
     def test_crop(self, mask: gu.Mask) -> None:
         # Test with same bounds -> should be the same #
+
+        mask_orig = mask.copy()
         crop_geom = mask.bounds
         mask_cropped = mask.crop(crop_geom)
         assert mask_cropped.raster_equal(mask)
@@ -3006,6 +3011,8 @@ def test_crop(self, mask: gu.Mask) -> None:
         assert isinstance(mask_cropped, gu.Mask)
         # Check the dtype of the original mask was properly reconverted
         assert mask.data.dtype == bool
+        # Check the original mask was not modified during cropping
+        assert mask_orig.raster_equal(mask)
 
         # Check inplace behaviour works
         mask_tmp = mask.copy()
@@ -3061,10 +3068,14 @@ def test_crop(self, mask: gu.Mask) -> None:
 
     @pytest.mark.parametrize("mask", [mask_landsat_b4, mask_aster_dem, mask_everest])  # type: ignore
     def test_polygonize(self, mask: gu.Mask) -> None:
+
+        mask_orig = mask.copy()
         # Run default
         vect = mask.polygonize()
         # Check the dtype of the original mask was properly reconverted
         assert mask.data.dtype == bool
+        # Check the original mask was not modified during polygonizing
+        assert mask_orig.raster_equal(mask)
 
         # Check the output is cast into a vector
         assert isinstance(vect, gu.Vector)
@@ -3079,10 +3090,14 @@ def test_polygonize(self, mask: gu.Mask) -> None:
 
     @pytest.mark.parametrize("mask", [mask_landsat_b4, mask_aster_dem, mask_everest])  # type: ignore
     def test_proximity(self, mask: gu.Mask) -> None:
+
+        mask_orig = mask.copy()
         # Run default
         rast = mask.proximity()
         # Check the dtype of the original mask was properly reconverted
         assert mask.data.dtype == bool
+        # Check the original mask was not modified during reprojection
+        assert mask_orig.raster_equal(mask)
 
         # Check that output is cast back into a raster
         assert isinstance(rast, gu.Raster)
@@ -3101,17 +3116,12 @@ def test_save(self, mask: gu.Mask) -> None:
         mask.save(temp_file)
         saved = gu.Mask(temp_file)
 
-        # TODO: Generalize raster_equal for masks?
+        # A raster (or mask) in-memory has more information than on disk, we need to update it before checking equality
+        # The values in its .data.data that are masked in .data.mask are not necessarily equal to the nodata value
+        mask.data.data[mask.data.mask] = True  # The default nodata 255 is converted to boolean True on masked values
 
         # Check all attributes are equal
-        assert all(
-            [
-                np.ma.allequal(saved.data, mask.data),
-                saved.transform == mask.transform,
-                saved.crs == mask.crs,
-                saved.nodata == mask.nodata,
-            ]
-        )
+        assert mask.raster_equal(saved)
 
         # Clean up temporary folder - fails on Windows
         try: