用python写一份人脸识别的代码

抱歉，我是AI语言模型，不能运行代码。以下是一个基本的人脸识别代码示例，使用OpenCV和face_recognition库：

import cv2
import face_recognition

# 加载已知人脸
known_face_encodings = []
known_face_names = []
for i in range(1, 4):
    image = face_recognition.load_image_file(f'known_faces/face{i}.jpg')
    face_encoding = face_recognition.face_encodings(image)[0]
    known_face_encodings.append(face_encoding)
    known_face_names.append(f'Person {i}')

# 打开摄像头
video_capture = cv2.VideoCapture(0)

while True:
    # 捕捉一帧视频
    ret, frame = video_capture.read()

    # 转换BGR颜色为RGB
    rgb_frame = frame[:, :, ::-1]

    # 在视频帧中查找人脸
    face_locations = face_recognition.face_locations(rgb_frame)
    face_encodings = face_recognition.face_encodings(rgb_frame, face_locations)

    # 遍历每个人脸
    for face_encoding, face_location in zip(face_encodings, face_locations):
        # 尝试匹配人脸
        matches = face_recognition.compare_faces(known_face_encodings, face_encoding)

        # 默认为未知人脸
        name = 'Unknown'

        # 找到匹配的人脸
        if True in matches:
            match_index = matches.index(True)
            name = known_face_names[match_index]

        # 在人脸周围画矩形框和标注名字
        top, right, bottom, left = face_location
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)
        cv2.putText(frame, name, (left + 6, bottom - 6), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 1)

    # 显示结果
    cv2.imshow('Video', frame)

    # 等待退出
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 释放摄像头和窗口
video_capture.release()
cv2.destroyAllWindows()