Object tracking follows instance labels through a series of frames in a video or image sequence.

By detecting and localizing objects in a frame, their position in subsequent frames is determined based on pixel information enclosed within the label boundary. All labels automatically created using interpolation are assigned a confidence score (α) of 99%.

Since tracking algorithms propagate labels forward through frames, object tracking works if labels are made on lower number frame (for example, near the start of the video).

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Ontologies

Ontology shapeInterpolationTracking
Bounding box✅✅
Rotatable bounding box✅✅
Polygon✅✅
Polyline✅✅
Primitive✅✅
Keypoint✅✅
Bitmask✅✅

* Polygon and Bitmasks use SAM 2 tracking

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Modalities

The following table shows the modalities that support SAM 2 tracking.

ModalitiesSAM 2 tracking
Images❌
Videos✅
Image Groups✅
Image Sequences✅
DICOM✅

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Quick Object Tracking

  1. Create at least one bounding box, bitmask, or polygon instance label on the frame you want to start tracking the instance from.
More manual instance labels on different frames result in high object tracking accuracy.

  1. Right-click the shape .

  2. Click Track object. For bounding boxes and rotatable bounding boxes, select the Standard (fast) option to run SAM 2 tracking for 30 consecutive frames.

Polyline, Keypoint, Object PrimitiveBounding Box, Rotatable Bounding Box

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Keyboard Shortcut

  1. Click the instance label.
  2. Use the Shift + T keyboard shortcut to the run object tracking for 30 frames. The tracking range can be adjusted in the settings.

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Fine Tune Object Tracking

  1. Create at least one instance label on the frame you want to start tracking the instance from.
More manual instance labels result in higher tracking accuracy.

  1. Click the Automated labelling button in the bottom left corner of the Label Editor to bring up options for automated labeling.

  2. The Tracking and interpolation section is open by default.

    • Under the Method heading, select Tracking.
    • Select the object instance you want to track.
    • The Tracking annotation interval lets you specify how many frames after a manual label the object is tracked for.
    • Tracking range specifies the total range of frames instances are tracked across.
    • The Advanced settings lets you choose between the Advanced and Standard tracking models. The Advanced model provides higher accuracy, but takes longer to run.

  3. Click Run tracking to track the instance.

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Settings

The Object tracking section of the editor settings allows you to adjust the tracking range, and choose between the standard or advanced tracking algorithm.