基于opencv的电脑摄像头简易人脸识别

import cv2 as cv
import keyboard
face_engine = cv.CascadeClassifier("E:\\python\\haarcascade_frontalface_default.xml")
eye_engine = cv.CascadeClassifier("E:\\python\\haarcascade_eye.xml")
smile_engine = cv.CascadeClassifier("E:\\python\\haarcascade_smile.xml")
cam = cv.VideoCapture(0)    #开启电脑自带的摄像头
while (True):
    ret, frame = cam.read()
    faces = face_engine.detectMultiScale(frame, scaleFactor=1.3, minNeighbors=3)
    image= frame
    for (x, y, w, h) in faces:
        image = cv.rectangle(image, (x, y), (x + w, y + h), (255, 0, 0), 5)   #用矩形框起人脸
        face_area = image[y:y + h, x:x + w]    #确定人脸范围
        eyes = eye_engine.detectMultiScale(face_area, scaleFactor=1.3, minNeighbors=10)   #在人脸范围内识别人眼
        for (ex, ey, ew, eh) in eyes:
            cv.rectangle(face_area, (ex, ey), (ex + ew, ey + eh), (0, 255, 0), 3)    #用矩形框起人眼
        smiles = smile_engine.detectMultiScale(face_area, scaleFactor=1.3, minNeighbors=10)   #在人脸范围内识别微笑
        for (sx, sy, sw, sh) in smiles:
            cv.rectangle(face_area, (sx, sy), (sx + sw, sy + sh), (0, 0, 255), 3)    #用矩形框起嘴巴轮廓
    cv.imshow("Face Recognition", image)
    cv.waitKey(5)

    #当键盘按下q键时退出识别
    if keyboard.is_pressed('q'):    
        break
cam.release()
cv.destroyAllWindows()