背景减法器不能在OpenCV Python中工作，该怎么办？

import cv2

# 创建背景减法器对象
bg_subtractor = cv2.createBackgroundSubtractorMOG2(history=500, varThreshold=16, detectShadows=False)

# 打开视频文件或摄像头
video_capture = cv2.VideoCapture('your_video.mp4')  # 或者使用 video_capture = cv2.VideoCapture(0)

while True:
    ret, frame = video_capture.read()
    if not ret:
        break

    # 应用背景减法
    fg_mask = bg_subtractor.apply(frame)

    # 对前景掩码进行形态学操作以去除噪声
    kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (5, 5))
    fg_mask = cv2.morphologyEx(fg_mask, cv2.MORPH_OPEN, kernel)
    fg_mask = cv2.morphologyEx(fg_mask, cv2.MORPH_CLOSE, kernel)

    # 将前景掩码应用到原始帧上
    result = cv2.bitwise_and(frame, frame, mask=fg_mask)

    # 显示结果
    cv2.imshow('Original', frame)
    cv2.imshow('Foreground Mask', fg_mask)
    cv2.imshow('Result', result)

    # 按 'q' 键退出循环
    if cv2.waitKey(30) & 0xFF == ord('q'):
        break

# 释放资源
video_capture.release()
cv2.destroyAllWindows()