def get_avg_fps(PIL_Image_object):
    """ Returns the average framerate of a PIL Image object """
    PIL_Image_object.seek(0)
    frames = duration = 0
    while True:
        try:
            frames += 1
            duration += PIL_Image_object.info['duration']
            PIL_Image_object.seek(PIL_Image_object.tell() + 1)
        except EOFError:
            return frames / duration * 1000
    return None