Base class for implementing aprocessor which filters the set of detection results, consistently delivering a single detected item to an associatedTracker.

Subclasses implement selectFocus(Detections) to define the criteria for initially selecting the detected item in which to "focus upon". Once selected, this same detected item will be sent to the tracker for as long as it exists in consecutive frames handled by a detector. That is, the tracking ID of the selected item, as included in the Detector.Detections.getDetectedItems() result, determines the selected item for subsequent frames. After the selected item is no longer visible, a new item will be selected as the focus.

For example, the code below creates and starts a pipeline that continuously receives preview frames from a camera source, runs detection on frames, and uses a focusing processor to continuously deliver a specific item of interest to a tracker over multiple frames.

detector.setProcessor(   new MyFooFocusingProcessor(     detector,     new MyFooTracker())); CameraSource cameraSource = new CameraSource.Builder(context, detector)   .build()   .start();