Handle invalid reduction values (#6675)

* Add ValueError

* Add tests for ValueError

* Add tests for ValueError

* Add ValueError

* Change to if/else

* Ammend iou_fn tests

* Move code excerpt

* Format tests
Co-authored-by: Philip Meier <github.pmeier@posteo.de>
Co-authored-by: Vasilis Vryniotis <datumbox@users.noreply.github.com>

test/test_ops.py

@@ -1394,6 +1394,11 @@ class TestGeneralizedBoxIouLoss:
         assert_iou_loss(ops.generalized_box_iou_loss, box1s, box2s, 2.5, device=device, reduction="sum")
         assert_iou_loss(ops.generalized_box_iou_loss, box1s, box2s, 1.25, device=device, reduction="mean")
 
+        # Test reduction value
+        # reduction value other than ["none", "mean", "sum"] should raise a ValueError
+        with pytest.raises(ValueError, match="Invalid"):
+            ops.generalized_box_iou_loss(box1s, box2s, reduction="xyz")
+
     @pytest.mark.parametrize("device", cpu_and_gpu())
     @pytest.mark.parametrize("dtype", [torch.float32, torch.half])
     def test_empty_inputs(self, dtype, device):
@@ -1413,6 +1418,9 @@ class TestCompleteBoxIouLoss:
         assert_iou_loss(ops.complete_box_iou_loss, box1s, box2s, 1.2250, device=device, reduction="mean")
         assert_iou_loss(ops.complete_box_iou_loss, box1s, box2s, 2.4500, device=device, reduction="sum")
 
+        with pytest.raises(ValueError, match="Invalid"):
+            ops.complete_box_iou_loss(box1s, box2s, reduction="xyz")
+
     @pytest.mark.parametrize("device", cpu_and_gpu())
     @pytest.mark.parametrize("dtype", [torch.float32, torch.half])
     def test_empty_inputs(self, dtype, device):
@@ -1432,6 +1440,9 @@ class TestDistanceBoxIouLoss:
         assert_iou_loss(ops.distance_box_iou_loss, box1s, box2s, 1.2250, device=device, reduction="mean")
         assert_iou_loss(ops.distance_box_iou_loss, box1s, box2s, 2.4500, device=device, reduction="sum")
 
+        with pytest.raises(ValueError, match="Invalid"):
+            ops.distance_box_iou_loss(box1s, box2s, reduction="xyz")
+
     @pytest.mark.parametrize("device", cpu_and_gpu())
     @pytest.mark.parametrize("dtype", [torch.float32, torch.half])
     def test_empty_distance_iou_inputs(self, dtype, device):
@@ -1554,6 +1565,17 @@ class TestFocalLoss:
         tol = 1e-3 if dtype is torch.half else 1e-5
         torch.testing.assert_close(focal_loss, scripted_focal_loss, rtol=tol, atol=tol)
 
+    # Raise ValueError for anonymous reduction mode
+    @pytest.mark.parametrize("device", cpu_and_gpu())
+    @pytest.mark.parametrize("dtype", [torch.float32, torch.half])
+    def test_reduction_mode(self, device, dtype, reduction="xyz"):
+        if device == "cpu" and dtype is torch.half:
+            pytest.skip("Currently torch.half is not fully supported on cpu")
+        torch.random.manual_seed(0)
+        inputs, targets = self._generate_diverse_input_target_pair(device=device, dtype=dtype)
+        with pytest.raises(ValueError, match="Invalid"):
+            ops.sigmoid_focal_loss(inputs, targets, 0.25, 2, reduction)
+
 
 class TestMasksToBoxes:
     def test_masks_box(self):

torchvision/ops/ciou_loss.py

@@ -63,9 +63,16 @@ def complete_box_iou_loss(
         alpha = v / (1 - iou + v + eps)
 
     loss = diou_loss + alpha * v
-    if reduction == "mean":
+
+    # Check reduction option and return loss accordingly
+    if reduction == "none":
+        pass
+    elif reduction == "mean":
         loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
     elif reduction == "sum":
         loss = loss.sum()
-
+    else:
+        raise ValueError(
+            f"Invalid Value for arg 'reduction': '{reduction} \n Supported reduction modes: 'none', 'mean', 'sum'"
+        )
     return loss

torchvision/ops/diou_loss.py

@@ -50,10 +50,17 @@ def distance_box_iou_loss(
 
     loss, _ = _diou_iou_loss(boxes1, boxes2, eps)
 
-    if reduction == "mean":
+    # Check reduction option and return loss accordingly
+    if reduction == "none":
+        pass
+    elif reduction == "mean":
         loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
     elif reduction == "sum":
         loss = loss.sum()
+    else:
+        raise ValueError(
+            f"Invalid Value for arg 'reduction': '{reduction} \n Supported reduction modes: 'none', 'mean', 'sum'"
+        )
     return loss
 
 

torchvision/ops/focal_loss.py

@@ -32,6 +32,7 @@ def sigmoid_focal_loss(
         Loss tensor with the reduction option applied.
     """
     # Original implementation from https://github.com/facebookresearch/fvcore/blob/master/fvcore/nn/focal_loss.py
+
     if not torch.jit.is_scripting() and not torch.jit.is_tracing():
         _log_api_usage_once(sigmoid_focal_loss)
     p = torch.sigmoid(inputs)
@@ -43,9 +44,15 @@ def sigmoid_focal_loss(
         alpha_t = alpha * targets + (1 - alpha) * (1 - targets)
         loss = alpha_t * loss
 
-    if reduction == "mean":
+    # Check reduction option and return loss accordingly
+    if reduction == "none":
+        pass
+    elif reduction == "mean":
         loss = loss.mean()
     elif reduction == "sum":
         loss = loss.sum()
-
+    else:
+        raise ValueError(
+            f"Invalid Value for arg 'reduction': '{reduction} \n Supported reduction modes: 'none', 'mean', 'sum'"
+        )
     return loss

torchvision/ops/giou_loss.py

@@ -62,9 +62,15 @@ def generalized_box_iou_loss(
 
     loss = 1 - miouk
 
-    if reduction == "mean":
+    # Check reduction option and return loss accordingly
+    if reduction == "none":
+        pass
+    elif reduction == "mean":
         loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
     elif reduction == "sum":
         loss = loss.sum()
-
+    else:
+        raise ValueError(
+            f"Invalid Value for arg 'reduction': '{reduction} \n Supported reduction modes: 'none', 'mean', 'sum'"
+        )
     return loss