def draw_approx_polyDP(cnt, epsilon=0.01, closed=True):
    '用多边形来近似的表示曲线'
    epsilon = (epsilon * cv2.arcLength(cnt, closed))
    return cv2.approxPolyDP(cnt, epsilon, closed)
用多边形来近似的表示曲线
def draw_approx_polyDP(cnt, epsilon=0.01, closed=True):
    
    epsilon = (epsilon * cv2.arcLength(cnt, closed))
    return cv2.approxPolyDP(cnt, epsilon, closed)