Python 人脸识别之谁偷用了我的电脑？

电脑没联网呢？或者摄像头打不开？

这个问题挺有意思的，用Python做人脸识别来抓“现行”完全可行。核心思路就是：用摄像头定时抓拍，然后和预设的“主人”人脸对比，如果不是就触发警报。

这里给你一个可以直接跑的完整例子，用了opencv-python和face_recognition这两个库。

首先，你得先装库：

pip install opencv-python face_recognition

下面是主程序代码：

import cv2
import face_recognition
import os
import pickle
from datetime import datetime
import time

class ComputerGuard:
    def __init__(self, owner_image_path, known_faces_file='known_faces.dat'):
        self.owner_image_path = owner_image_path
        self.known_faces_file = known_faces_file
        self.owner_encoding = None
        self.known_face_encodings = []
        self.known_face_names = []
        
        # 加载或创建已知人脸数据
        self.load_known_faces()
        
    def load_owner_face(self):
        """加载电脑主人的面部编码"""
        if not os.path.exists(self.owner_image_path):
            print(f"错误：找不到主人图片 {self.owner_image_path}")
            return False
            
        owner_image = face_recognition.load_image_file(self.owner_image_path)
        owner_encodings = face_recognition.face_encodings(owner_image)
        
        if len(owner_encodings) == 0:
            print("错误：在主人图片中未检测到人脸")
            return False
            
        self.owner_encoding = owner_encodings[0]
        return True
        
    def load_known_faces(self):
        """加载已知人脸数据库"""
        if os.path.exists(self.known_faces_file):
            with open(self.known_faces_file, 'rb') as f:
                data = pickle.load(f)
                self.known_face_encodings = data['encodings']
                self.known_face_names = data['names']
        else:
            # 初始化空数据库
            self.known_face_encodings = []
            self.known_face_names = []
            
        # 加载主人面部编码
        if self.load_owner_face():
            # 将主人添加到已知人脸库
            if "主人" not in self.known_face_names:
                self.known_face_encodings.append(self.owner_encoding)
                self.known_face_names.append("主人")
                self.save_known_faces()
                
    def save_known_faces(self):
        """保存已知人脸数据库"""
        data = {
            'encodings': self.known_face_encodings,
            'names': self.known_face_names
        }
        with open(self.known_faces_file, 'wb') as f:
            pickle.dump(data, f)
            
    def add_known_face(self, face_encoding, name):
        """添加新的人脸到已知库"""
        self.known_face_encodings.append(face_encoding)
        self.known_face_names.append(name)
        self.save_known_faces()
        
    def monitor(self, check_interval=5, confidence_threshold=0.6):
        """开始监控"""
        if self.owner_encoding is None:
            print("错误：未加载主人面部编码")
            return
            
        video_capture = cv2.VideoCapture(0)
        last_check_time = time.time()
        
        print("监控已启动，按 'q' 键退出...")
        
        while True:
            ret, frame = video_capture.read()
            
            if not ret:
                print("无法获取视频流")
                break
                
            current_time = time.time()
            
            # 定时检查
            if current_time - last_check_time >= check_interval:
                # 转换颜色空间（face_recognition需要RGB）
                rgb_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
                
                # 检测人脸
                face_locations = face_recognition.face_locations(rgb_frame)
                face_encodings = face_recognition.face_encodings(rgb_frame, face_locations)
                
                if len(face_encodings) > 0:
                    # 与主人对比
                    matches = face_recognition.compare_faces([self.owner_encoding], face_encodings[0])
                    face_distances = face_recognition.face_distance([self.owner_encoding], face_encodings[0])
                    
                    is_owner = matches[0] and face_distances[0] < confidence_threshold
                    
                    if not is_owner:
                        # 发现陌生人！
                        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
                        stranger_name = f"陌生人_{timestamp}"
                        
                        # 保存截图
                        filename = f"stranger_{timestamp}.jpg"
                        cv2.imwrite(filename, frame)
                        print(f"警报！检测到陌生人，已保存截图: {filename}")
                        
                        # 添加到已知人脸库（可选）
                        self.add_known_face(face_encodings[0], stranger_name)
                        
                        # 这里可以添加其他警报逻辑，比如发送邮件、播放声音等
                        # print("触发警报！")
                        
                    else:
                        print(f"{datetime.now().strftime('%H:%M:%S')} - 识别通过：主人")
                        
                last_check_time = current_time
                
            # 显示实时画面
            cv2.imshow('Computer Guard', frame)
            
            # 按q退出
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
                
        video_capture.release()
        cv2.destroyAllWindows()

# 使用示例
if __name__ == "__main__":
    # 准备一张你的清晰正面照片，命名为 owner.jpg 放在同一目录
    guard = ComputerGuard(owner_image_path='owner.jpg')
    guard.monitor(check_interval=3)  # 每3秒检查一次

代码说明：