Merge pull request #59 from lsst/tickets/DM-53448

DM-53448: Stitch mask and variance planes correctly when some cells have no coverage

Author: arunkannawadi

python/lsst/cell_coadds/_stitched_image_planes.py

@@ -28,6 +28,8 @@
 from functools import partial
 from typing import TYPE_CHECKING, TypeVar
 
+import numpy as np
+
 from lsst.afw.image import ImageF, Mask
 
 from . import typing_helpers
@@ -107,7 +109,9 @@ def uncache_image(self) -> None:
     def mask(self) -> Mask:
         # Docstring inherited.
         if self._mask is None:
-            self._mask = self._make_plane(Mask(self.bbox), lambda planes: planes.mask)
+            self._mask = self._make_plane(
+                Mask(self.bbox, Mask.getPlaneBitMask("NO_DATA")), lambda planes: planes.mask
+            )
         return self._mask
 
     def uncache_mask(self) -> None:
@@ -118,7 +122,7 @@ def uncache_mask(self) -> None:
     def variance(self) -> ImageLike:
         # Docstring inherited.
         if self._variance is None:
-            self._variance = self._make_plane(ImageF(self.bbox), lambda planes: planes.variance)
+            self._variance = self._make_plane(ImageF(self.bbox, np.inf), lambda planes: planes.variance)
         return self._variance
 
     def uncache_variance(self) -> None: