# 导入cv模块
import cv2 as cv


# 检测函数
def detect_face(img):
    gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
    face_cascade = cv.CascadeClassifier(
        "D:/PythonProject/opencv-4.11.0-install/opencv/sources/data/haarcascades/haarcascade_frontalface_default.xml"
    )
    faces = face_cascade.detectMultiScale(gray)
    for x, y, w, h in faces:
        cv.rectangle(img, (x, y), (x + w, y + h), color=(255, 0, 0), thickness=2)
    cv.imshow("result_img", img)


# 读取摄像头 0 默认的摄像头 其他的数字是其他设备摄像头
cap = cv.VideoCapture(0)
# 等待
while cap.isOpened():
    flag, frame = cap.read()
    if not flag:
        break  # 读取失败
    detect_face(frame)
    if ord(" ") == cv.waitKey(0):
        break
# 释放内存
cv.destroyAllWindows()
# 释放摄像头
cap.release()