When bounding boxes are cached in metadata, don’t crash on load_masks=False

Summary:
We currently support caching bounding boxes in MaskAnnotation. If present, they are not re-computed from the mask. However, the masks need to be loaded for the bbox to be set.

This diff fixes that. Even if load_masks / load_blobs are unset, the bounding box can be picked up from the metadata.

Reviewed By: bottler

Differential Revision: D45144918

fbshipit-source-id: 8a2e2c115e96070b6fcdc29cbe57e1cee606ddcd

pytorch3d/implicitron/dataset/frame_data.py

@@ -555,12 +555,19 @@ class GenericFrameDataBuilder(FrameDataBuilderBase[FrameDataSubtype], ABC):
             else None,
         )
 
-        if load_blobs and self.load_masks and frame_annotation.mask is not None:
-            (
-                frame_data.fg_probability,
-                frame_data.mask_path,
-                frame_data.bbox_xywh,
-            ) = self._load_fg_probability(frame_annotation)
+        mask_annotation = frame_annotation.mask
+        if mask_annotation is not None:
+            fg_mask_np: Optional[np.ndarray] = None
+            if load_blobs and self.load_masks:
+                fg_mask_np, mask_path = self._load_fg_probability(frame_annotation)
+                frame_data.mask_path = mask_path
+                frame_data.fg_probability = safe_as_tensor(fg_mask_np, torch.float)
+
+            bbox_xywh = mask_annotation.bounding_box_xywh
+            if bbox_xywh is None and fg_mask_np is not None:
+                bbox_xywh = get_bbox_from_mask(fg_mask_np, self.box_crop_mask_thr)
+
+            frame_data.bbox_xywh = safe_as_tensor(bbox_xywh, torch.long)
 
         if frame_annotation.image is not None:
             image_size_hw = safe_as_tensor(frame_annotation.image.size, torch.long)
@@ -604,25 +611,15 @@ class GenericFrameDataBuilder(FrameDataBuilderBase[FrameDataSubtype], ABC):
 
     def _load_fg_probability(
         self, entry: types.FrameAnnotation
-    ) -> Tuple[Optional[torch.Tensor], Optional[str], Optional[torch.Tensor]]:
-
+    ) -> Tuple[np.ndarray, str]:
         full_path = os.path.join(self.dataset_root, entry.mask.path)  # pyre-ignore
         fg_probability = load_mask(self._local_path(full_path))
-        # we can use provided bbox_xywh or calculate it based on mask
-        # saves time to skip bbox calculation
-        # pyre-ignore
-        bbox_xywh = entry.mask.bounding_box_xywh or get_bbox_from_mask(
-            fg_probability, self.box_crop_mask_thr
-        )
         if fg_probability.shape[-2:] != entry.image.size:
             raise ValueError(
                 f"bad mask size: {fg_probability.shape[-2:]} vs {entry.image.size}!"
             )
-        return (
-            safe_as_tensor(fg_probability, torch.float),
-            full_path,
-            safe_as_tensor(bbox_xywh, torch.long),
-        )
+
+        return fg_probability, full_path
 
     def _load_images(
         self,

tests/implicitron/test_frame_data_builder.py

@@ -17,6 +17,7 @@ from pytorch3d.implicitron.dataset import types
 from pytorch3d.implicitron.dataset.dataset_base import FrameData
 from pytorch3d.implicitron.dataset.frame_data import FrameDataBuilder
 from pytorch3d.implicitron.dataset.utils import (
+    get_bbox_from_mask,
     load_16big_png_depth,
     load_1bit_png_mask,
     load_depth,
@@ -107,11 +108,14 @@ class TestFrameDataBuilder(TestCaseMixin, unittest.TestCase):
         )
         self.frame_data.effective_image_size_hw = self.frame_data.image_size_hw
 
-        (
-            self.frame_data.fg_probability,
-            self.frame_data.mask_path,
-            self.frame_data.bbox_xywh,
-        ) = self.frame_data_builder._load_fg_probability(self.frame_annotation)
+        fg_mask_np, mask_path = self.frame_data_builder._load_fg_probability(
+            self.frame_annotation
+        )
+        self.frame_data.mask_path = mask_path
+        self.frame_data.fg_probability = safe_as_tensor(fg_mask_np, torch.float)
+        mask_thr = self.frame_data_builder.box_crop_mask_thr
+        bbox_xywh = get_bbox_from_mask(fg_mask_np, mask_thr)
+        self.frame_data.bbox_xywh = safe_as_tensor(bbox_xywh, torch.long)
 
         self.assertIsNotNone(self.frame_data.mask_path)
         self.assertTrue(torch.is_tensor(self.frame_data.fg_probability))