MediaPipeTasksVision Framework Reference


protocol GestureRecognizerLiveStreamDelegate : NSObjectProtocol

This protocol defines an interface for the delegates of GestureRecognizer object to receive results of performing asynchronous gesture recognition on images (i.e, when runningMode = .liveStream).

The delegate of GestureRecognizer must adopt GestureRecognizerLiveStreamDelegate protocol. The methods in this protocol are optional.

  • This method notifies a delegate that the results of asynchronous gesture recognition of an image submitted to the GestureRecognizer is available.

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



    optional func gestureRecognizer(_ gestureRecognizer: MPPGestureRecognizer, didFinishGestureRecognition result: GestureRecognizerResult?, timestampInMilliseconds: Int, error: Error?)



    The gesture recognizer which performed the gesture recognition. This is useful to test equality when there are multiple instances of GestureRecognizer.


    The GestureRecognizerResult 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 gesture recognizer.


    An optional error parameter populated when there is an error in performing gesture recognition on the input live stream image data.