def rect_to_bounding_box(rect):
    """
    Method for converting the dlib's rect object
    to standard --coordinates of (x1, y1) and (x2, y2)
    :param rect:
    :return tuple: (x1, y1, x2, y2)
    """
    x = rect.left()
    y = rect.top()
    w = rect.right() - x
    h = rect.bottom() - y

    return x, y, w, h