def kalman_test(vid_src):
    _, frame = vid_src.read()
    used_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    model = KalmanFilter(used_frame, 60)

    # applying background detection
    while frame is not None:

        used_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

        fg = model.apply(used_frame)

        cv2.imshow('img', used_frame)
        cv2.imshow('fg', fg)

        prev_frame = np.copy(frame)
        _, frame = vid_src.read()

        # print model.get_background_model().get_density_range(used_frame)

        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    pass