我无法在代码中理解我的错误：“ TypeError：UMat（）缺少必需的参数'ranges（位置2）“

Question

我正在上一堂有关OpenCV的课程，以了解相机上是否有东西移动。当我测试它时，它不起作用，并显示：

  

TypeError：UMat（）缺少必需的参数“范围”（位置2）

我已经引用了这篇文章，但是无法解决我的问题：OpenCV TypeError: Expected cv::UMat for argument 'src' - What is this?

import cv2

def fram_diff(prev_frame, cur_frame, next_frame):

    diff_frames_1=cv2.absdiff(next_frame, cur_frame)
    diff_frames_2=cv2.absdiff(cur_frame, prev_frame)
    return cv2.bitwise_and(diff_frames_1, diff_frames_2)

def get_frame(cap, scaling_factor):

    frame = cap.read() 
    frame = cv2.resize(cv2.UMat(frame), None, fx=scaling_factor, fy=scaling_factor, interpolation=cv2.INTER_AREA)
    gray = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY)

    return gray

if __name__=='__main__':

    cap = cv2.VideoCapture(0)
    scaling_factor=0.5
    prev_frame = get_frame(cap, scaling_factor)
    cur_frame = get_frame(cap, scaling_factor)
    next_frame = get_frame(cap, scaling_factor)
    while True:
        cv2.imshow('Object Movement', fram_diff(prev_frame,cur_frame, next_frame))
        prev_frame=cur_frame
        cur_frame=next_frame
        next_frame=get_frame(cap, scaling_factor)
        key=cv2.waitKey(10)

        if key==27:
            break
    cv2.destroyAllWindows()

我的错误是：

line 19, in <module>
    prev_frame = get_frame(cap, scaling_factor)

line 12, in get_frame
    frame = cv2.resize(cv2.UMat(frame), None, fx=scaling_factor, fy=scaling_factor, interpolation=cv2.INTER_AREA)

TypeError: UMat() missing required argument 'ranges' (pos 2)

我刚刚发现了问题所在！它在函数get_frame中。

要更正我的代码，我已替换行：

frame = cap.read() 

按行

ret, frame = cap.read()