only allow 1 image or bounding box instead of 1 or 2 (#6531)

torchvision/prototype/transforms/_utils.py

@@ -14,7 +14,7 @@ def query_bounding_box(sample: Any) -> features.BoundingBox:
     bounding_boxes = {item for item in flat_sample if isinstance(item, features.BoundingBox)}
     if not bounding_boxes:
         raise TypeError("No bounding box was found in the sample")
-    elif len(bounding_boxes) > 2:
+    elif len(bounding_boxes) > 1:
         raise ValueError("Found multiple bounding boxes in the sample")
     return bounding_boxes.pop()
 
@@ -28,7 +28,7 @@ def query_chw(sample: Any) -> Tuple[int, int, int]:
     }
     if not chws:
         raise TypeError("No image was found in the sample")
-    elif len(chws) > 2:
+    elif len(chws) > 1:
         raise ValueError(f"Found multiple CxHxW dimensions in the sample: {sequence_to_str(sorted(chws))}")
     return chws.pop()