Google Vision api :How to detect face detected is

问题:

I am using google vision api for face detection in my app. its working fine but in my case i need to deal with only real human faces. but my app is considering there faces in photo as a face. but i want to detect which is photo and which is live image.

below is the class of face graphics

 private class GraphicFaceTracker extends Tracker<Face> {
    private GraphicOverlay mOverlay;
    private FaceGraphic mFaceGraphic;

    GraphicFaceTracker(GraphicOverlay overlay) {
        mOverlay = overlay;
        mFaceGraphic = new FaceGraphic(overlay);
    }

    /**
     * Start tracking the detected face instance within the face overlay.
     */
    @Override
    public void onNewItem(int faceId, Face item) {
        FaceTrackerActivity.faceId = faceId;
        mFaceGraphic.setId(faceId);
    }

    /**
     * Update the position/characteristics of the face within the overlay.
     */
    @Override
    public void onUpdate(FaceDetector.Detections<Face> detectionResults, Face face) {
        mOverlay.add(mFaceGraphic);
        mFaceGraphic.updateFace(face);
       //here face detected live or image

    }

    /**
     * Hide the graphic when the corresponding face was not detected.  This can happen for
     * intermediate frames temporarily (e.g., if the face was momentarily blocked from
     * view).
     */
    @Override
    public void onMissing(FaceDetector.Detections<Face> detectionResults) {
        mOverlay.remove(mFaceGraphic);
    }

    /**
     * Called when the face is assumed to be gone for good. Remove the graphic annotation from
     * the overlay.
     */
    @Override
    public void onDone() {
        mOverlay.remove(mFaceGraphic);
        Log.d("Gajanand", "onDone: ");
    }

}

any help?