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negative_frame

sleap.gui.overlays.negative_frame

Overlay highlighting frames marked as negative (background) frames.

Classes:

Name Description
NegativeFrameOverlay

Draws a blue border and caption when the current frame is negative.

NegativeFrameOverlay

Bases: BaseOverlay

Draws a blue border and caption when the current frame is negative.

A negative frame is explicitly marked as containing no animals. This overlay gives an unmissable on-canvas cue so the state is obvious while labeling, mirroring how unconverted predictions are highlighted.

Attributes:

Name Type Description
labels Labels | None

The :class:Labels dataset from which to get overlay data.
player QtVideoPlayer | None

The video player in which to show the overlay.

Methods:

Name Description
add_to_scene

Adds the negative-frame border and caption to the player scene.
Source code in sleap/gui/overlays/negative_frame.py 
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@attr.s(auto_attribs=True)
class NegativeFrameOverlay(BaseOverlay):
    """Draws a blue border and caption when the current frame is negative.

    A negative frame is explicitly marked as containing no animals. This overlay
    gives an unmissable on-canvas cue so the state is obvious while labeling,
    mirroring how unconverted predictions are highlighted.

    Attributes:
        labels: The :class:`Labels` dataset from which to get overlay data.
        player: The video player in which to show the overlay.
    """

    def add_to_scene(self, video, frame_idx):
        """Adds the negative-frame border and caption to the player scene."""
        self.items = []

        if self.labels is None or video is None or frame_idx is None:
            return

        lf = self.labels.find(video, frame_idx, return_new=True)[0]
        if not lf.is_negative:
            return

        frame_rect = self.player.scene.sceneRect()
        if frame_rect.isEmpty():
            return

        color = QColor(*NEGATIVE_FRAME_COLOR)

        # Thick border just inside the periphery of the whole frame. The rect is
        # inset slightly so the stroke stays fully visible when the view is fit
        # exactly to the frame; the pen is cosmetic so its width is constant
        # regardless of zoom.
        inset_x = frame_rect.width() * 0.012
        inset_y = frame_rect.height() * 0.012
        border_rect = QRectF(
            frame_rect.left() + inset_x,
            frame_rect.top() + inset_y,
            frame_rect.width() - 2 * inset_x,
            frame_rect.height() - 2 * inset_y,
        )
        border = QGraphicsRectItem(border_rect)
        border_pen = QPen(color, 6)
        border_pen.setCosmetic(True)
        border.setPen(border_pen)
        self.player.scene.addItem(border)
        self.items.append(border)

        # "Negative Frame" caption pinned to the top-left corner. The text item
        # ignores view transformations, so it stays a constant on-screen size.
        caption = QtTextWithBackground()
        caption.setDefaultTextColor(color)
        font = caption.font()
        font.setPointSize(14)
        font.setBold(True)
        caption.setFont(font)
        caption.setPlainText("Negative Frame")
        caption.setPos(border_rect.topLeft())
        self.player.scene.addItem(caption)
        self.items.append(caption)

add_to_scene(video, frame_idx)

Adds the negative-frame border and caption to the player scene.

Source code in sleap/gui/overlays/negative_frame.py 
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def add_to_scene(self, video, frame_idx):
    """Adds the negative-frame border and caption to the player scene."""
    self.items = []

    if self.labels is None or video is None or frame_idx is None:
        return

    lf = self.labels.find(video, frame_idx, return_new=True)[0]
    if not lf.is_negative:
        return

    frame_rect = self.player.scene.sceneRect()
    if frame_rect.isEmpty():
        return

    color = QColor(*NEGATIVE_FRAME_COLOR)

    # Thick border just inside the periphery of the whole frame. The rect is
    # inset slightly so the stroke stays fully visible when the view is fit
    # exactly to the frame; the pen is cosmetic so its width is constant
    # regardless of zoom.
    inset_x = frame_rect.width() * 0.012
    inset_y = frame_rect.height() * 0.012
    border_rect = QRectF(
        frame_rect.left() + inset_x,
        frame_rect.top() + inset_y,
        frame_rect.width() - 2 * inset_x,
        frame_rect.height() - 2 * inset_y,
    )
    border = QGraphicsRectItem(border_rect)
    border_pen = QPen(color, 6)
    border_pen.setCosmetic(True)
    border.setPen(border_pen)
    self.player.scene.addItem(border)
    self.items.append(border)

    # "Negative Frame" caption pinned to the top-left corner. The text item
    # ignores view transformations, so it stays a constant on-screen size.
    caption = QtTextWithBackground()
    caption.setDefaultTextColor(color)
    font = caption.font()
    font.setPointSize(14)
    font.setBold(True)
    caption.setFont(font)
    caption.setPlainText("Negative Frame")
    caption.setPos(border_rect.topLeft())
    self.player.scene.addItem(caption)
    self.items.append(caption)