roboflow/supervision · error · ValueError

MetricTarget.MASKS is not currently supported for ConfusionM

Error message

MetricTarget.MASKS is not currently supported for ConfusionMatrix.

What it means

Error "MetricTarget.MASKS is not currently supported for ConfusionMatrix." thrown in roboflow/supervision.

Source

Thrown at src/supervision/metrics/detection.py:34

)

from supervision.config import ORIENTED_BOX_COORDINATES
from supervision.dataset.core import DetectionDataset
from supervision.detection.core import Detections
from supervision.detection.utils.iou_and_nms import (
    box_iou_batch,
    oriented_box_iou_batch,
)
from supervision.metrics.core import MetricTarget
from supervision.metrics.utils.matching import _greedy_match

if TYPE_CHECKING:
    from matplotlib.figure import Figure


def _assert_supported_target(metric_target: MetricTarget) -> None:
    if metric_target == MetricTarget.MASKS:
        raise ValueError(
            "MetricTarget.MASKS is not currently supported for ConfusionMatrix."
        )


def _validated_class_ids(
    values: npt.NDArray[np.float32],
    num_classes: int,
    role: str,
) -> npt.NDArray[np.int64]:
    """Return class ids that are safe to use as confusion-matrix indexes."""
    if values.size == 0:
        return np.asarray(values, dtype=np.int64)

    finite = np.isfinite(values)
    integral = values == np.floor(values)
    if not np.all(finite & integral):
        raise ValueError(f"{role} class ids must be finite integers.")

View on GitHub (pinned to 7f254d9784)

Solutions

1. ConfusionMatrix does not support MetricTarget.MASKS; use MetricTarget.BOXES or ORIENTED_BOUNDING_BOXES.
2. To evaluate masks, use MeanAveragePrecision/MeanAverageRecall with MetricTarget.MASKS instead.

When it happens

Trigger: Thrown at src/supervision/metrics/detection.py:34 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of roboflow/supervision@7f254d9784 (2026-08-15). Data as JSON: /api/errors/7bf3c78314fa2d6f. Report an issue: GitHub.