This protocol defines an interface for the delegates of FaceDetector face to receive
results of performing asynchronous face detection on images (i.e, when runningMode =
.liveStream).
The delegate of FaceDetector must adopt FaceDetectorLiveStreamDelegate protocol.
The methods in this protocol are optional.
The face detector which performed the face detection.
This is useful to test equality when there are multiple instances of FaceDetector.
result
The FaceDetectorResult 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.
timestampInMilliseconds
The timestamp (in milliseconds) which indicates when the input
image was sent to the face detector.
error
An optional error parameter populated when there is an error in performing face
detection on the input live stream image data.