paquo.images: support loading annotations if image file is not available

paquo/images.py

@@ -6,11 +6,13 @@
 from typing import Iterator, Optional, Any, List
 
 from paquo._base import QuPathBase
-from paquo._logging import redirect
+from paquo._logging import redirect, get_logger
 from paquo._utils import cached_property
 from paquo.hierarchy import QuPathPathObjectHierarchy
 from paquo.java import String, DefaultProjectImageEntry, ImageType, ImageData, IOException, URI, URISyntaxException
 
+_log = get_logger(__name__)
+
 
 class ImageProvider(ABC):
     """Maps image ids to paths and paths to image ids."""
@@ -366,7 +368,11 @@ def properties(self, value):
     @cached_property
     def hierarchy(self) -> QuPathPathObjectHierarchy:
         """the image entry hierarchy. it contains all annotations"""
-        return QuPathPathObjectHierarchy(self._image_data.getHierarchy())
+        try:
+            return QuPathPathObjectHierarchy(self._image_data.getHierarchy())
+        except OSError:
+            _log.warning("could not open image data. loading annotation hierarchy from project.")
+            return QuPathPathObjectHierarchy(self.java_object.readHierarchy())
 
     def __repr__(self):
         return f"<ImageEntry('{self.image_name}')>"