如何使用OpenCV_Contrib检测视频中的地标？

import cv2
import cv2.contrib

# 加载视频
video = cv2.VideoCapture('your_video.mp4')

# 创建ORB地标检测器
orb = cv2.contrib.ORB.create()

while True:
    # 读取视频帧
    ret, frame = video.read()
    
    if not ret:
        break
    
    # 将帧转换为灰度图像
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    
    # 检测地标
    keypoints, descriptors = orb.detectAndCompute(gray, None)
    
    # 在图像上绘制地标
    frame_with_keypoints = cv2.drawKeypoints(frame, keypoints, None, color=(0, 255, 0), flags=0)
    
    # 显示图像
    cv2.imshow('Video', frame_with_keypoints)
    
    # 按下'q'键退出循环
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 释放视频和窗口
video.release()
cv2.destroyAllWindows()