Class PoseTracker

PoseTracker keeps track of a landmarks for a single pose. This is useful for tracking the movement of a pose or its landmarks over time. It does this by making a PointTracker for each keypoint of a pose.

Note: You probably don't want to create this yourself! Rather, use a PosesTracker to access.

Example

// Create a tracker (fromId is the id of sender, poseId is the id of the pose)
const pt = new PoseTracker(fromId, poseId, options);
// ...and whenever there is data, call .seen()
pt.seen(pose);

When creating, the most useful tuning options are sampleLimit which governs how many of the most recent samples to keep, and storeIntermediate (true/false) to store intermediate data.

Accessing keypoints

You can get the raw keypoint data from the pose

// Get a single point
const nosePoint = pose.landmarkValue(`nose`); // { x, y, score, name }
// Get all points
for (const kp of poses.landmarkValues()) {
// { x, y, score, name }
}

But the real power comes from getting the PointTracker for a keypoint, since it keeps track of not just the last data, but a whole trail of historical data for a given keypoint.

const noseTracker = pose.landmark(`nose`); // PointTracker

Once we have the PointTracker, there are a lot of things to access:

Constructors

constructor

Accessors

elapsed fromId guid height heightWorld hsl hue last middle middleWorld peerId poseId width widthWorld zRange zRangeWorld

Methods

box boxWorld centroid getByDistanceFromPoint getClosestLandmarkToPoint getFurtherest getHighest getLeftmost getLowest getNearest getRightmost getSortedByX getSortedByY getSortedByZ landmark landmarkValue landmarkValues landmarks reset seen worldLandmark worldLandmarkValue worldLandmarkValues worldLandmarks

Constructors

constructor

Accessors

elapsed

fromId

guid

height

heightWorld

hsl

hue

last

middle

  • get middle(): Point | {
        x: 0;
        y: 0;
    }

  • Returns the middle of the pose bounding box using normalised coordinates

    pose.middle; // { x, y }

    Returns Point | {
        x: 0;
        y: 0;
    }

middleWorld

peerId

poseId

  • get poseId(): string

  • Returns the original pose id from TFjs Warning: this may not be unique if there are multiple senders

    Returns string

width

widthWorld

zRange

zRangeWorld

Methods

box

  • box(...namesOrIds): RectPositioned | Readonly<{
        height: 0;
        width: 0;
        x: 0;
        y: 0;
    }>

  • Gets the bounding box of the pose, computed using the normalised landmarks.

    pose.box(); // { x, y, width, height }

    Returns an empty rectangle if there's no data.

    You can also provide a list of landmark names/indexes to compute the bounding box for just those:

    // Get bounding box of torso
    pose.box(`left_shoulder`, `right_shoulder`, `left_hip`, `right_`hip`);

    See also {@link boxWorld} for same behaviour but using world coordinates.

    Parameters

    Returns RectPositioned | Readonly<{
        height: 0;
        width: 0;
        x: 0;
        y: 0;
    }>

boxWorld

  • boxWorld(...namesOrIds): RectPositioned | Readonly<{
        height: 0;
        width: 0;
        x: 0;
        y: 0;
    }>

  • Parameters

    Returns RectPositioned | Readonly<{
        height: 0;
        width: 0;
        x: 0;
        y: 0;
    }>

centroid

  • centroid(...namesOrIds): Point

  • Returns the 2D centroid of all the pose points (uses normalised landmarks)

    pose.centroid(); // { x, y }

    Or you can pass in the names/indexes of landmarks:

    pose.centroid(`left_shoulder`, `right_shoulder`);

    Returns { x: 0.5, y: 0.5 } is data is missing

    Parameters

    Returns Point

getByDistanceFromPoint

getClosestLandmarkToPoint

getFurtherest

getHighest

getLeftmost

getLowest

getNearest

getRightmost

getSortedByX

getSortedByY

getSortedByZ

landmark

  • landmark(nameOrIndex): undefined | PointTracker<NormalizedLandmark>

  • Returns a PointTracker for a given normalised landmark by name or index.

    // Eg. get tracker for the 'nose' landmark
    const nose = pose.landmark(`nose`);

    // Get the angle of nose movement since the start
    const a = nose.angleFromStart();

    // Get the distance of nose since start
    const d = nose.distanceFromStart();

    Parameters

    Returns undefined | PointTracker<NormalizedLandmark>

landmarkValue

landmarkValues

landmarks

  • landmarks(...namesOrIds): Generator<PointTracker<NormalizedLandmark>, void, undefined>

  • Returns all the PointTrackers (ie. landmark) for this pose.

    for (const pt of pose.landmarks()) {
     // Do something with 'pt' (which tracks one individual landmark)
    }

    Or provide a list of landmark indexes or name:

    // Get landmarks for right arm
    for (const pt of pose.landmarks(11, 13, 15)) {
    }

    Parameters

    Returns Generator<PointTracker<NormalizedLandmark>, void, undefined>

reset

seen

worldLandmark

  • worldLandmark(nameOrIndex): undefined | PointTracker<Landmark>

  • Returns a PointTracker for a given normalised landmark by name or index.

    // Eg. get tracker for the 'nose' landmark
    const nose = pose.landmark(`nose`);

    // Get the angle of nose movement since the start
    const a = nose.angleFromStart();

    // Get the distance of nose since start
    const d = nose.distanceFromStart();

    Parameters

    Returns undefined | PointTracker<Landmark>

worldLandmarkValue

worldLandmarkValues

worldLandmarks

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Accessing keypoints
Constructors
Accessors
Methods