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labeled_frame

sleap_io.model.labeled_frame

Data structures for data contained within a single video frame.

The LabeledFrame class is a data structure that contains Instances and PredictedInstances that are associated with a single frame within a video.

LabeledFrame

Labeled data for a single frame of a video.

Attributes:

Name Type Description
video Video

The Video associated with this LabeledFrame.

frame_idx int

The index of the LabeledFrame in the Video.

instances list[Union[Instance, PredictedInstance]]

List of Instance objects associated with this LabeledFrame.

Notes

Instances of this class are hashed by identity, not by value. This means that two LabeledFrame instances with the same attributes will NOT be considered equal in a set or dict.

Source code in sleap_io/model/labeled_frame.py
@define(eq=False)
class LabeledFrame:
    """Labeled data for a single frame of a video.

    Attributes:
        video: The `Video` associated with this `LabeledFrame`.
        frame_idx: The index of the `LabeledFrame` in the `Video`.
        instances: List of `Instance` objects associated with this `LabeledFrame`.

    Notes:
        Instances of this class are hashed by identity, not by value. This means that
        two `LabeledFrame` instances with the same attributes will NOT be considered
        equal in a set or dict.
    """

    video: Video
    frame_idx: int
    instances: list[Union[Instance, PredictedInstance]] = field(factory=list)

    def __len__(self) -> int:
        """Return the number of instances in the frame."""
        return len(self.instances)

    def __getitem__(self, key: int) -> Union[Instance, PredictedInstance]:
        """Return the `Instance` at `key` index in the `instances` list."""
        return self.instances[key]

    def __iter__(self):
        """Iterate over `Instance`s in `instances` list."""
        return iter(self.instances)

    @property
    def user_instances(self) -> list[Instance]:
        """Frame instances that are user-labeled (`Instance` objects)."""
        return [inst for inst in self.instances if type(inst) == Instance]

    @property
    def has_user_instances(self) -> bool:
        """Return True if the frame has any user-labeled instances."""
        for inst in self.instances:
            if type(inst) == Instance:
                return True
        return False

    @property
    def predicted_instances(self) -> list[Instance]:
        """Frame instances that are predicted by a model (`PredictedInstance` objects)."""
        return [inst for inst in self.instances if type(inst) == PredictedInstance]

    @property
    def has_predicted_instances(self) -> bool:
        """Return True if the frame has any predicted instances."""
        for inst in self.instances:
            if type(inst) == PredictedInstance:
                return True
        return False

    def numpy(self) -> np.ndarray:
        """Return all instances in the frame as a numpy array.

        Returns:
            Points as a numpy array of shape `(n_instances, n_nodes, 2)`.

            Note that the order of the instances is arbitrary.
        """
        n_instances = len(self.instances)
        n_nodes = len(self.instances[0]) if n_instances > 0 else 0
        pts = np.full((n_instances, n_nodes, 2), np.nan)
        for i, inst in enumerate(self.instances):
            pts[i] = inst.numpy()[:, 0:2]
        return pts

    @property
    def image(self) -> np.ndarray:
        """Return the image of the frame as a numpy array."""
        return self.video[self.frame_idx]

    @property
    def unused_predictions(self) -> list[Instance]:
        """Return a list of "unused" `PredictedInstance` objects in frame.

        This is all of the `PredictedInstance` objects which do not have a corresponding
        `Instance` in the same track in the same frame.
        """
        unused_predictions = []
        any_tracks = [inst.track for inst in self.instances if inst.track is not None]
        if len(any_tracks):
            # Use tracks to determine which predicted instances have been used
            used_tracks = [
                inst.track
                for inst in self.instances
                if type(inst) == Instance and inst.track is not None
            ]
            unused_predictions = [
                inst
                for inst in self.instances
                if inst.track not in used_tracks and type(inst) == PredictedInstance
            ]

        else:
            # Use from_predicted to determine which predicted instances have been used
            # TODO: should we always do this instead of using tracks?
            used_instances = [
                inst.from_predicted
                for inst in self.instances
                if inst.from_predicted is not None
            ]
            unused_predictions = [
                inst
                for inst in self.instances
                if type(inst) == PredictedInstance and inst not in used_instances
            ]

        return unused_predictions

    def remove_predictions(self):
        """Remove all `PredictedInstance` objects from the frame."""
        self.instances = [inst for inst in self.instances if type(inst) == Instance]

    def remove_empty_instances(self):
        """Remove all instances with no visible points."""
        self.instances = [inst for inst in self.instances if not inst.is_empty]

has_predicted_instances: bool property

Return True if the frame has any predicted instances.

has_user_instances: bool property

Return True if the frame has any user-labeled instances.

image: np.ndarray property

Return the image of the frame as a numpy array.

predicted_instances: list[Instance] property

Frame instances that are predicted by a model (PredictedInstance objects).

unused_predictions: list[Instance] property

Return a list of "unused" PredictedInstance objects in frame.

This is all of the PredictedInstance objects which do not have a corresponding Instance in the same track in the same frame.

user_instances: list[Instance] property

Frame instances that are user-labeled (Instance objects).

__getitem__(key)

Return the Instance at key index in the instances list.

Source code in sleap_io/model/labeled_frame.py
def __getitem__(self, key: int) -> Union[Instance, PredictedInstance]:
    """Return the `Instance` at `key` index in the `instances` list."""
    return self.instances[key]

__iter__()

Iterate over Instances in instances list.

Source code in sleap_io/model/labeled_frame.py
def __iter__(self):
    """Iterate over `Instance`s in `instances` list."""
    return iter(self.instances)

__len__()

Return the number of instances in the frame.

Source code in sleap_io/model/labeled_frame.py
def __len__(self) -> int:
    """Return the number of instances in the frame."""
    return len(self.instances)

numpy()

Return all instances in the frame as a numpy array.

Returns:

Type Description
ndarray

Points as a numpy array of shape (n_instances, n_nodes, 2).

Note that the order of the instances is arbitrary.

Source code in sleap_io/model/labeled_frame.py
def numpy(self) -> np.ndarray:
    """Return all instances in the frame as a numpy array.

    Returns:
        Points as a numpy array of shape `(n_instances, n_nodes, 2)`.

        Note that the order of the instances is arbitrary.
    """
    n_instances = len(self.instances)
    n_nodes = len(self.instances[0]) if n_instances > 0 else 0
    pts = np.full((n_instances, n_nodes, 2), np.nan)
    for i, inst in enumerate(self.instances):
        pts[i] = inst.numpy()[:, 0:2]
    return pts

remove_empty_instances()

Remove all instances with no visible points.

Source code in sleap_io/model/labeled_frame.py
def remove_empty_instances(self):
    """Remove all instances with no visible points."""
    self.instances = [inst for inst in self.instances if not inst.is_empty]

remove_predictions()

Remove all PredictedInstance objects from the frame.

Source code in sleap_io/model/labeled_frame.py
def remove_predictions(self):
    """Remove all `PredictedInstance` objects from the frame."""
    self.instances = [inst for inst in self.instances if type(inst) == Instance]