MediaPipeTasksVision Framework Reference


protocol HandLandmarkerLiveStreamDelegate : NSObjectProtocol

This protocol defines an interface for the delegates of HandLandmarker object to receive results of performing asynchronous hand landmark detection on images (i.e, when runningMode = .liveStream).

The delegate of HandLandmarker must adopt HandLandmarkerLiveStreamDelegate protocol. The methods in this protocol are optional.

  • This method notifies a delegate that the results of asynchronous hand landmark detection of an image submitted to the HandLandmarker is available.

    This method is called on a private serial dispatch queue created by the HandLandmarker for performing the asynchronous delegates calls.



    optional func handLandmarker(_ handLandmarker: MPPHandLandmarker, didFinishDetection result: HandLandmarkerResult?, timestampInMilliseconds: Int, error: Error?)



    The hand landmarker which performed the hand landmarking. This is useful to test equality when there are multiple instances of HandLandmarker.


    The HandLandmarkerResult object that contains a list of detections, each detection has a bounding box that is expressed in the unrotated input frame of reference coordinates system, i.e. in [0,image_width) x [0,image_height), which are the dimensions of the underlying image data.


    The timestamp (in milliseconds) which indicates when the input image was sent to the hand landmarker.


    An optional error parameter populated when there is an error in performing hand landmark detection on the input live stream image data.