estimatePoseSingleMarkers从 version 4.7 起不再存在，这里我用SolvePnP代替了这个函数：

def my_estimatePoseSingleMarkers(corners, marker_size, mtx, distortion):
    '''
    This will estimate the rvec and tvec for each of the marker corners detected by:
       corners, ids, rejectedImgPoints = detector.detectMarkers(image)
    corners - is an array of detected corners for each detected marker in the image
    marker_size - is the size of the detected markers
    mtx - is the camera matrix
    distortion - is the camera distortion matrix
    RETURN list of rvecs, tvecs, and trash (so that it corresponds to the old estimatePoseSingleMarkers())
    '''
    marker_points = np.array([[-marker_size / 2, marker_size / 2, 0],
                              [marker_size / 2, marker_size / 2, 0],
                              [marker_size / 2, -marker_size / 2, 0],
                              [-marker_size / 2, -marker_size / 2, 0]], dtype=np.float32)
    trash = []
    rvecs = []
    tvecs = []
    i = 0
    for c in corners:
        nada, R, t = cv2.solvePnP(marker_points, corners[i], mtx, distortion, False, cv2.SOLVEPNP_IPPE_SQUARE)
        rvecs.append(R)
        tvecs.append(t)
        trash.append(nada)
    return rvecs, tvecs, trash