Not sure why following two boxes return 0 for box_iou value
import torchvision.ops as ops
b1 = torch.tensor([167, 238, 249, 276]).view(1, -1)
b2 = torch.tensor([146, 230, 228, 268]).view(1, -1)
print(ops.boxes.box_iou(b1, b2))

They look like nicely overlapped.
What I am missing?
Thanks in advance