Adjust clamping for rotated bboxes (#9112)

Co-authored-by: Nicolas Hug <contact@nicolas-hug.com>

Author: AntoineSimoulin

test/common_utils.py

@@ -21,7 +21,7 @@
 from torch.testing._comparison import BooleanPair, NonePair, not_close_error_metas, NumberPair, TensorLikePair
 from torchvision import io, tv_tensors
 from torchvision.transforms._functional_tensor import _max_value as get_max_value
-from torchvision.transforms.v2.functional import clamp_bounding_boxes, to_image, to_pil_image
+from torchvision.transforms.v2.functional import to_image, to_pil_image
 
 
 IN_OSS_CI = any(os.getenv(var) == "true" for var in ["CIRCLECI", "GITHUB_ACTIONS"])
@@ -410,7 +410,7 @@ def make_bounding_boxes(
     canvas_size=DEFAULT_SIZE,
     *,
     format=tv_tensors.BoundingBoxFormat.XYXY,
-    clamping_mode="hard",  # TODOBB
+    clamping_mode="soft",
     num_boxes=1,
     dtype=None,
     device="cpu",
@@ -469,21 +469,6 @@ def sample_position(values, max_value):
     else:
         raise ValueError(f"Format {format} is not supported")
     out_boxes = torch.stack(parts, dim=-1).to(dtype=dtype, device=device)
-    if tv_tensors.is_rotated_bounding_format(format):
-        # The rotated bounding boxes are not guaranteed to be within the canvas by design,
-        # so we apply clamping. We also add a 2 buffer to the canvas size to avoid
-        # numerical issues during the testing
-        buffer = 4
-        out_boxes = clamp_bounding_boxes(
-            out_boxes,
-            format=format,
-            canvas_size=(canvas_size[0] - buffer, canvas_size[1] - buffer),
-            clamping_mode=clamping_mode,
-        )
-        if format is tv_tensors.BoundingBoxFormat.XYWHR or format is tv_tensors.BoundingBoxFormat.CXCYWHR:
-            out_boxes[:, :2] += buffer // 2
-        elif format is tv_tensors.BoundingBoxFormat.XYXYXYXY:
-            out_boxes[:, :] += buffer // 2
     return tv_tensors.BoundingBoxes(out_boxes, format=format, canvas_size=canvas_size, clamping_mode=clamping_mode)
 
 

test/test_transforms_v2.py

@@ -551,6 +551,7 @@ def affine_bounding_boxes(bounding_boxes):
         ),
         format=format,
         canvas_size=canvas_size,
+        clamping_mode=clamping_mode,
     )
 
 
@@ -639,6 +640,7 @@ def affine_rotated_bounding_boxes(bounding_boxes):
         ).reshape(bounding_boxes.shape),
         format=format,
         canvas_size=canvas_size,
+        clamping_mode=clamping_mode,
     )
 
 
@@ -1305,7 +1307,7 @@ def _reference_horizontal_flip_bounding_boxes(self, bounding_boxes: tv_tensors.B
             if tv_tensors.is_rotated_bounding_format(bounding_boxes.format)
             else reference_affine_bounding_boxes_helper
         )
-        return helper(bounding_boxes, affine_matrix=affine_matrix)
+        return helper(bounding_boxes, affine_matrix=affine_matrix, clamp=False)
 
     @pytest.mark.parametrize("format", list(tv_tensors.BoundingBoxFormat))
     @pytest.mark.parametrize(
@@ -1914,7 +1916,7 @@ def _reference_vertical_flip_bounding_boxes(self, bounding_boxes: tv_tensors.Bou
             if tv_tensors.is_rotated_bounding_format(bounding_boxes.format)
             else reference_affine_bounding_boxes_helper
         )
-        return helper(bounding_boxes, affine_matrix=affine_matrix)
+        return helper(bounding_boxes, affine_matrix=affine_matrix, clamp=False)
 
     @pytest.mark.parametrize("format", list(tv_tensors.BoundingBoxFormat))
     @pytest.mark.parametrize("fn", [F.vertical_flip, transform_cls_to_functional(transforms.RandomVerticalFlip, p=1)])
@@ -2079,7 +2081,6 @@ def test_functional(self, make_input):
             (F.rotate_image, torch.Tensor),
             (F._geometry._rotate_image_pil, PIL.Image.Image),
             (F.rotate_image, tv_tensors.Image),
-            (F.rotate_bounding_boxes, tv_tensors.BoundingBoxes),
             (F.rotate_mask, tv_tensors.Mask),
             (F.rotate_video, tv_tensors.Video),
             (F.rotate_keypoints, tv_tensors.KeyPoints),
@@ -2229,29 +2230,26 @@ def _reference_rotate_bounding_boxes(self, bounding_boxes, *, angle, expand, cen
             clamp=False,
         )
 
-        return F.clamp_bounding_boxes(self._recenter_bounding_boxes_after_expand(output, recenter_xy=recenter_xy)).to(
-            bounding_boxes
-        )
+        return self._recenter_bounding_boxes_after_expand(output, recenter_xy=recenter_xy).to(bounding_boxes)
 
     @pytest.mark.parametrize("format", list(tv_tensors.BoundingBoxFormat))
     @pytest.mark.parametrize("angle", _CORRECTNESS_AFFINE_KWARGS["angle"])
     @pytest.mark.parametrize("expand", [False, True])
     @pytest.mark.parametrize("center", _CORRECTNESS_AFFINE_KWARGS["center"])
     def test_functional_bounding_boxes_correctness(self, format, angle, expand, center):
-        bounding_boxes = make_bounding_boxes(format=format)
+        bounding_boxes = make_bounding_boxes(format=format, clamping_mode="none")
 
         actual = F.rotate(bounding_boxes, angle=angle, expand=expand, center=center)
         expected = self._reference_rotate_bounding_boxes(bounding_boxes, angle=angle, expand=expand, center=center)
-
-        torch.testing.assert_close(actual, expected)
         torch.testing.assert_close(F.get_size(actual), F.get_size(expected), atol=2 if expand else 0, rtol=0)
+        torch.testing.assert_close(actual, expected)
 
     @pytest.mark.parametrize("format", list(tv_tensors.BoundingBoxFormat))
     @pytest.mark.parametrize("expand", [False, True])
     @pytest.mark.parametrize("center", _CORRECTNESS_AFFINE_KWARGS["center"])
     @pytest.mark.parametrize("seed", list(range(5)))
     def test_transform_bounding_boxes_correctness(self, format, expand, center, seed):
-        bounding_boxes = make_bounding_boxes(format=format)
+        bounding_boxes = make_bounding_boxes(format=format, clamping_mode="none")
 
         transform = transforms.RandomRotation(**self._CORRECTNESS_TRANSFORM_AFFINE_RANGES, expand=expand, center=center)
 
@@ -2262,9 +2260,8 @@ def test_transform_bounding_boxes_correctness(self, format, expand, center, seed
         actual = transform(bounding_boxes)
 
         expected = self._reference_rotate_bounding_boxes(bounding_boxes, **params, expand=expand, center=center)
-
-        torch.testing.assert_close(actual, expected)
         torch.testing.assert_close(F.get_size(actual), F.get_size(expected), atol=2 if expand else 0, rtol=0)
+        torch.testing.assert_close(actual, expected)
 
     def _recenter_keypoints_after_expand(self, keypoints, *, recenter_xy):
         x, y = recenter_xy
@@ -4349,7 +4346,6 @@ def test_functional(self, make_input):
             (F.resized_crop_image, torch.Tensor),
             (F._geometry._resized_crop_image_pil, PIL.Image.Image),
             (F.resized_crop_image, tv_tensors.Image),
-            (F.resized_crop_bounding_boxes, tv_tensors.BoundingBoxes),
             (F.resized_crop_mask, tv_tensors.Mask),
             (F.resized_crop_video, tv_tensors.Video),
             (F.resized_crop_keypoints, tv_tensors.KeyPoints),
@@ -4415,6 +4411,7 @@ def _reference_resized_crop_bounding_boxes(self, bounding_boxes, *, top, left, h
                 [0, 0, 1],
             ],
         )
+
         affine_matrix = (resize_affine_matrix @ crop_affine_matrix)[:2, :]
 
         helper = (
@@ -4423,15 +4420,15 @@ def _reference_resized_crop_bounding_boxes(self, bounding_boxes, *, top, left, h
             else reference_affine_bounding_boxes_helper
         )
 
-        return helper(
-            bounding_boxes,
-            affine_matrix=affine_matrix,
-            new_canvas_size=size,
-        )
+        return helper(bounding_boxes, affine_matrix=affine_matrix, new_canvas_size=size, clamp=False)
 
     @pytest.mark.parametrize("format", list(tv_tensors.BoundingBoxFormat))
     def test_functional_bounding_boxes_correctness(self, format):
-        bounding_boxes = make_bounding_boxes(self.INPUT_SIZE, format=format)
+        # Note that we don't want to clamp because in
+        # _reference_resized_crop_bounding_boxes we are fusing the crop and the
+        # resize operation, where none of the croppings happen - particularly,
+        # the intermediate one.
+        bounding_boxes = make_bounding_boxes(self.INPUT_SIZE, format=format, clamping_mode="none")
 
         actual = F.resized_crop(bounding_boxes, **self.CROP_KWARGS, size=self.OUTPUT_SIZE)
         expected = self._reference_resized_crop_bounding_boxes(

test/test_tv_tensors.py

@@ -406,3 +406,8 @@ def test_return_type_input():
         tv_tensors.set_return_type("typo")
 
     tv_tensors.set_return_type("tensor")
+
+
+def test_box_clamping_mode_default():
+    assert tv_tensors.BoundingBoxes([0, 0, 10, 10], format="XYXY", canvas_size=(100, 100)).clamping_mode == "soft"
+    assert tv_tensors.BoundingBoxes([0, 0, 10, 10, 0], format="XYWHR", canvas_size=(100, 100)).clamping_mode == "soft"

torchvision/transforms/v2/functional/_geometry.py

@@ -522,7 +522,7 @@ def resize_bounding_boxes(
     size: Optional[list[int]],
     max_size: Optional[int] = None,
     format: tv_tensors.BoundingBoxFormat = tv_tensors.BoundingBoxFormat.XYXY,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
     # We set the default format as `tv_tensors.BoundingBoxFormat.XYXY`
     # to ensure backward compatibility.
@@ -1108,15 +1108,16 @@ def _affine_bounding_boxes_with_expand(
     shear: list[float],
     center: Optional[list[float]] = None,
     expand: bool = False,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
     if bounding_boxes.numel() == 0:
         return bounding_boxes, canvas_size
 
     original_shape = bounding_boxes.shape
     dtype = bounding_boxes.dtype
-    need_cast = not bounding_boxes.is_floating_point()
-    bounding_boxes = bounding_boxes.float() if need_cast else bounding_boxes.clone()
+    acceptable_dtypes = [torch.float64]  # Ensure consistency between CPU and GPU.
+    need_cast = dtype not in acceptable_dtypes
+    bounding_boxes = bounding_boxes.to(torch.float64) if need_cast else bounding_boxes.clone()
     device = bounding_boxes.device
     is_rotated = tv_tensors.is_rotated_bounding_format(format)
     intermediate_format = tv_tensors.BoundingBoxFormat.XYXYXYXY if is_rotated else tv_tensors.BoundingBoxFormat.XYXY
@@ -1210,7 +1211,7 @@ def affine_bounding_boxes(
     scale: float,
     shear: list[float],
     center: Optional[list[float]] = None,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> torch.Tensor:
     out_box, _ = _affine_bounding_boxes_with_expand(
         bounding_boxes,
@@ -1448,6 +1449,7 @@ def rotate_bounding_boxes(
     angle: float,
     expand: bool = False,
     center: Optional[list[float]] = None,
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
     return _affine_bounding_boxes_with_expand(
         bounding_boxes,
@@ -1459,6 +1461,7 @@ def rotate_bounding_boxes(
         shear=[0.0, 0.0],
         center=center,
         expand=expand,
+        clamping_mode=clamping_mode,
     )
 
 
@@ -1473,6 +1476,7 @@ def _rotate_bounding_boxes_dispatch(
         angle=angle,
         expand=expand,
         center=center,
+        clamping_mode=inpt.clamping_mode,
     )
     return tv_tensors.wrap(output, like=inpt, canvas_size=canvas_size)
 
@@ -1739,7 +1743,7 @@ def pad_bounding_boxes(
     canvas_size: tuple[int, int],
     padding: list[int],
     padding_mode: str = "constant",
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
     if padding_mode not in ["constant"]:
         # TODO: add support of other padding modes
@@ -1857,7 +1861,7 @@ def crop_bounding_boxes(
     left: int,
     height: int,
     width: int,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
 
     # Crop or implicit pad if left and/or top have negative values:
@@ -2097,7 +2101,7 @@ def perspective_bounding_boxes(
     startpoints: Optional[list[list[int]]],
     endpoints: Optional[list[list[int]]],
     coefficients: Optional[list[float]] = None,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> torch.Tensor:
     if bounding_boxes.numel() == 0:
         return bounding_boxes
@@ -2412,7 +2416,7 @@ def elastic_bounding_boxes(
     format: tv_tensors.BoundingBoxFormat,
     canvas_size: tuple[int, int],
     displacement: torch.Tensor,
-    clamping_mode: CLAMPING_MODE_TYPE = "hard",  # TODOBB soft
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> torch.Tensor:
     expected_shape = (1, canvas_size[0], canvas_size[1], 2)
     if not isinstance(displacement, torch.Tensor):
@@ -2433,19 +2437,19 @@ def elastic_bounding_boxes(
 
     original_shape = bounding_boxes.shape
     # TODO: first cast to float if bbox is int64 before convert_bounding_box_format
-    intermediate_format = tv_tensors.BoundingBoxFormat.XYXYXYXY if is_rotated else tv_tensors.BoundingBoxFormat.XYXY
+    intermediate_format = tv_tensors.BoundingBoxFormat.CXCYWHR if is_rotated else tv_tensors.BoundingBoxFormat.XYXY
 
     bounding_boxes = (
         convert_bounding_box_format(bounding_boxes.clone(), old_format=format, new_format=intermediate_format)
-    ).reshape(-1, 8 if is_rotated else 4)
+    ).reshape(-1, 5 if is_rotated else 4)
 
     id_grid = _create_identity_grid(canvas_size, device=device, dtype=dtype)
     # We construct an approximation of inverse grid as inv_grid = id_grid - displacement
     # This is not an exact inverse of the grid
     inv_grid = id_grid.sub_(displacement)
 
     # Get points from bboxes
-    points = bounding_boxes if is_rotated else bounding_boxes[:, [[0, 1], [2, 1], [2, 3], [0, 3]]]
+    points = bounding_boxes[:, :2] if is_rotated else bounding_boxes[:, [[0, 1], [2, 1], [2, 3], [0, 3]]]
     points = points.reshape(-1, 2)
     if points.is_floating_point():
         points = points.ceil_()
@@ -2457,8 +2461,8 @@ def elastic_bounding_boxes(
     transformed_points = inv_grid[0, index_y, index_x, :].add_(1).mul_(0.5 * t_size).sub_(0.5)
 
     if is_rotated:
-        transformed_points = transformed_points.reshape(-1, 8)
-        out_bboxes = _parallelogram_to_bounding_boxes(transformed_points).to(bounding_boxes.dtype)
+        transformed_points = transformed_points.reshape(-1, 2)
+        out_bboxes = torch.cat([transformed_points, bounding_boxes[:, 2:]], dim=1).to(bounding_boxes.dtype)
     else:
         transformed_points = transformed_points.reshape(-1, 4, 2)
         out_bbox_mins, out_bbox_maxs = torch.aminmax(transformed_points, dim=1)
@@ -2619,11 +2623,18 @@ def center_crop_bounding_boxes(
     format: tv_tensors.BoundingBoxFormat,
     canvas_size: tuple[int, int],
     output_size: list[int],
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
     crop_height, crop_width = _center_crop_parse_output_size(output_size)
     crop_top, crop_left = _center_crop_compute_crop_anchor(crop_height, crop_width, *canvas_size)
     return crop_bounding_boxes(
-        bounding_boxes, format, top=crop_top, left=crop_left, height=crop_height, width=crop_width
+        bounding_boxes,
+        format,
+        top=crop_top,
+        left=crop_left,
+        height=crop_height,
+        width=crop_width,
+        clamping_mode=clamping_mode,
     )
 
 
@@ -2632,7 +2643,11 @@ def _center_crop_bounding_boxes_dispatch(
     inpt: tv_tensors.BoundingBoxes, output_size: list[int]
 ) -> tv_tensors.BoundingBoxes:
     output, canvas_size = center_crop_bounding_boxes(
-        inpt.as_subclass(torch.Tensor), format=inpt.format, canvas_size=inpt.canvas_size, output_size=output_size
+        inpt.as_subclass(torch.Tensor),
+        format=inpt.format,
+        canvas_size=inpt.canvas_size,
+        output_size=output_size,
+        clamping_mode=inpt.clamping_mode,
     )
     return tv_tensors.wrap(output, like=inpt, canvas_size=canvas_size)
 
@@ -2779,17 +2794,29 @@ def resized_crop_bounding_boxes(
     height: int,
     width: int,
     size: list[int],
+    clamping_mode: CLAMPING_MODE_TYPE = "soft",
 ) -> tuple[torch.Tensor, tuple[int, int]]:
-    bounding_boxes, canvas_size = crop_bounding_boxes(bounding_boxes, format, top, left, height, width)
-    return resize_bounding_boxes(bounding_boxes, format=format, canvas_size=canvas_size, size=size)
+    bounding_boxes, canvas_size = crop_bounding_boxes(
+        bounding_boxes, format, top, left, height, width, clamping_mode=clamping_mode
+    )
+    return resize_bounding_boxes(
+        bounding_boxes, format=format, canvas_size=canvas_size, size=size, clamping_mode=clamping_mode
+    )
 
 
 @_register_kernel_internal(resized_crop, tv_tensors.BoundingBoxes, tv_tensor_wrapper=False)
 def _resized_crop_bounding_boxes_dispatch(
     inpt: tv_tensors.BoundingBoxes, top: int, left: int, height: int, width: int, size: list[int], **kwargs
 ) -> tv_tensors.BoundingBoxes:
     output, canvas_size = resized_crop_bounding_boxes(
-        inpt.as_subclass(torch.Tensor), format=inpt.format, top=top, left=left, height=height, width=width, size=size
+        inpt.as_subclass(torch.Tensor),
+        format=inpt.format,
+        top=top,
+        left=left,
+        height=height,
+        width=width,
+        size=size,
+        clamping_mode=inpt.clamping_mode,
     )
     return tv_tensors.wrap(output, like=inpt, canvas_size=canvas_size)