Fix non-rotated format to rotated format conversion logic (#8926)

Co-authored-by: Nicolas Hug <[email protected]>
Co-authored-by: Nicolas Hug <[email protected]>

Author: AntoineSimoulin

torchvision/transforms/v2/functional/_meta.py

@@ -263,13 +263,24 @@ def _xyxyxyxy_to_xywhr(xyxyxyxy: torch.Tensor, inplace: bool) -> torch.Tensor:
     return xyxyxyxy[..., :5].to(dtype)
 
 
+def is_rotated_bounding_box_format(format: BoundingBoxFormat) -> bool:
+    return format.value in [
+        BoundingBoxFormat.XYWHR.value,
+        BoundingBoxFormat.CXCYWHR.value,
+        BoundingBoxFormat.XYXYXYXY.value,
+    ]
+
+
 def _convert_bounding_box_format(
     bounding_boxes: torch.Tensor, old_format: BoundingBoxFormat, new_format: BoundingBoxFormat, inplace: bool = False
 ) -> torch.Tensor:
 
     if new_format == old_format:
         return bounding_boxes
 
+    if is_rotated_bounding_box_format(old_format) ^ is_rotated_bounding_box_format(new_format):
+        raise ValueError("Cannot convert between rotated and unrotated bounding boxes.")
+
     # TODO: Add _xywh_to_cxcywh and _cxcywh_to_xywh to improve performance
     if old_format == BoundingBoxFormat.XYWH:
         bounding_boxes = _xywh_to_xyxy(bounding_boxes, inplace)

torchvision/tv_tensors/_bounding_boxes.py

@@ -20,7 +20,7 @@ class BoundingBoxFormat(Enum):
     * ``XYWHR``: rotated boxes represented via corner, width and height, x1, y1
       being top left, w, h being width and height. r is rotation angle in
       degrees.
-    * ``CXCYWHR``: jrotated boxes represented via centre, width and height, cx,
+    * ``CXCYWHR``: rotated boxes represented via centre, width and height, cx,
       cy being center of box, w, h being width and height. r is rotation angle
       in degrees.
     * ``XYXYXYXY``: rotated boxes represented via corners, x1, y1 being top