我正在执行 Face_Detection 程序，但输出并未显示一些警告

Question

import cv2

import numpy as np

# https://github.com/Itseez/opencv/tree/master/data/haarcascade

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')

videocapture = cv2.VideoCapture(0)

scale_factor = 1.3

while 1:

    ret, pic = videocapture.read()

    faces = face_cascade.detectMultiScale(pic, scale_factor, 5)

    for(x, y, w, h) in faces:

        cv2.rectangle(pic, (x, y), (x + w, y + h), (255, 0, 0), 2)

        font = cv2.FONT_HERSHEY_SIMPLEX

        cv2.putText(pic, 'Me', (x, y), font, 2, (255, 255, 255), 2, cv2.LINE_AA)

        print("Number of faces found {} " .format(len(faces)))

        cv2.imshow('faces', pic)

        k = cv2.waitKey(30) & 0xff

        if k == 2:

            break

            cv2.destroyAllWindows()

[警告：0] 全局 C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-2y91i_7w\opencv\modules\videoio\src\cap_msmf.cpp (435) `anonymous-namespace':: SourceReaderCB::~SourceReaderCB 终止异步回调

Answer 1

我已经得到了此警告的答案，因为我不允许我的相机启动，所以在允许我的相机后它已成功运行