上述代码中报错，NameError: name 'track_window' is not defined，怎么修改

可以在代码中定义变量track_window，例如：

import cv2

# 读取图像
img = cv2.imread('test.jpg')

# 定义 ROI
x, y, w, h = 100, 100, 200, 200
track_window = (x, y, w, h)

# 创建窗口并显示图像
cv2.namedWindow('image')
cv2.imshow('image', img)

# 选择初始目标区域
roi = img[y:y+h, x:x+w]
hsv_roi = cv2.cvtColor(roi, cv2.COLOR_BGR2HSV)
mask = cv2.inRange(hsv_roi, (0, 60, 32), (180, 255, 255))
roi_hist = cv2.calcHist([hsv_roi], [0], mask, [180], [0, 180])
cv2.normalize(roi_hist, roi_hist, 0, 255, cv2.NORM_MINMAX)

# 创建终止条件
term_crit = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 1)

# 循环处理视频帧
while True:
    # 读取视频帧
    ret, frame = cap.read()
    if not ret:
        break

    # 将视频帧转换为 HSV 空间
    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    # 计算反向投影图
    dst = cv2.calcBackProject([hsv], [0], roi_hist, [0, 180], 1)

    # 进行均值漂移
    ret, track_window = cv2.meanShift(dst, track_window, term_crit)

    # 绘制目标区域
    x, y, w, h = track_window
    img2 = cv2.rectangle(frame, (x, y), (x+w, y+h), 255, 2)
    cv2.imshow('image', img2)

    # 等待按键
    if cv2.waitKey(60) == 27:
        break

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