Add crop/expand method to GeoBox

odc/geo/geobox.py

@@ -853,6 +853,17 @@ def pad_wh(self, alignx: int = 16, aligny: MaybeInt = None) -> "GeoBox":
 
         return GeoBox((ny, nx), self._affine, self._crs)
 
+    def crop(self, shape: SomeShape) -> "GeoBox":
+        """
+        Crop or expand to a given shape.
+
+        :returns: New :py:class:`~odc.geo.geobox.GeoBox` with a new shape,
+                 top left pixel remains at the same location and scale.
+        """
+        return GeoBox(shape, self._affine, self._crs)
+
+    expand = crop
+
     def zoom_out(self, factor: float) -> "GeoBox":
         """
         Compute :py:class:`~odc.geo.geobox.GeoBox` with changed resolution.

tests/test_geobox.py

@@ -601,3 +601,21 @@ def test_qr2sample(n, with_edges):
     assert (gbox.project(xx1) - gbox.extent).is_empty
     assert (xx1 - gbox.project(gbox.extent)).is_empty
     assert (xx2 - gbox.project(gbox.extent)).is_empty
+
+
+_gbox = GeoBox((3, 17), mkA(scale=(10, -10), translation=(1000, -20)), epsg3857)
+
+
+@pytest.mark.parametrize(
+    ("gbox", "shape"),
+    [
+        (_gbox, (1, 1)),
+        (_gbox, (100, 200)),
+        (_gbox, (200, 100)),
+    ],
+)
+def test_crop(gbox, shape):
+    assert gbox.crop(shape).shape == shape
+    assert gbox.crop(shape).crs == gbox.crs
+    assert gbox.crop(shape)[:1, :1] == gbox[:1, :1]
+    assert gbox.crop(shape) == gbox.expand(shape)