人脸认证:face_recognition库的安装与应用

xiaohai 2025-08-26 21:20:11 40人围观 标签: Python 
简介人脸识别技术如今已广泛应用于安全监控、身份验证、人机交互等多个领域。对于开发者而言,利用现有的库如face_recognition可以极大地简化人脸识别的开发过程。本文将详细介绍如何安装face_recognition库,并通过实例展示如何用它来实现一个基本的人脸比对服务。
一、face_recognition库的安装

face_recognition是一个基于Python的开源库,它使用dlib库中的[机器学习]模型进行人脸识别。
安装命令:

pip install face_recognition
二、人脸比对的实现
2.1 加载图片并识别人脸

face_recognition提供了简单直观的API来加载图片并识别其中的人脸。

import face_recognition

# 加载图片
image1 = face_recognition.load_image_file('image1.jpg')
image2 = face_recognition.load_image_file('image2.jpg')

# 识别图片中的人脸
face_encodings1 = face_recognition.face_encodings(image1)[0]
face_encodings2 = face_recognition.face_encodings(image2)[0]
2.2 比对人脸

识别出人脸后,我们可以使用face_recognition.compare_facesface_recognition.face_distance来比对两个或更多人脸。

  • 使用compare_faces:返回布尔值列表,表示每一对人脸是否匹配。

    results = face_recognition.compare_faces([face_encodings1], face_encodings2)
    print(results)  # 例如: [True] 表示匹配成功

  • 使用face_distance:返回人脸编码之间的欧氏距离,距离越小表示越相似。

    distance = face_recognition.face_distance([face_encodings1], face_encodings2)
    print(distance)  # 距离值,可以根据实际情况设置阈值来判断是否相似

三、完整例子
import face_recognition

picture_of_me = face_recognition.load_image_file("1.jpg")
my_face_encoding = face_recognition.face_encodings(picture_of_me)[0]


unknown_picture = face_recognition.load_image_file("2.jpg")
unknown_face_encoding = face_recognition.face_encodings(unknown_picture)[0]


results = face_recognition.compare_faces([my_face_encoding], unknown_face_encoding)

if results[0] == True:
    print("It's a picture of me!")
else:
    print("It's not a picture of me!")
四、调用本地摄像头示例

官方实例:face_recognition/examples/facerec_from_webcam_faster.py at master · ageitgey/face_recognition · GitHub

import face_recognition
import cv2
import numpy as np

# This is a demo of running face recognition on live video from your webcam. It's a little more complicated than the
# other example, but it includes some basic performance tweaks to make things run a lot faster:
#   1. Process each video frame at 1/4 resolution (though still display it at full resolution)
#   2. Only detect faces in every other frame of video.

# PLEASE NOTE: This example requires OpenCV (the `cv2` library) to be installed only to read from your webcam.
# OpenCV is *not* required to use the face_recognition library. It's only required if you want to run this
# specific demo. If you have trouble installing it, try any of the other demos that don't require it instead.

# Get a reference to webcam #0 (the default one)
video_capture = cv2.VideoCapture(0)

# Load a sample picture and learn how to recognize it.
obama_image = face_recognition.load_image_file("obama.jpg")
obama_face_encoding = face_recognition.face_encodings(obama_image)[0]

# Load a second sample picture and learn how to recognize it.
biden_image = face_recognition.load_image_file("biden.jpg")
biden_face_encoding = face_recognition.face_encodings(biden_image)[0]

# Create arrays of known face encodings and their names
known_face_encodings = [
    obama_face_encoding,
    biden_face_encoding
]
known_face_names = [
    "Barack Obama",
    "Joe Biden"
]

# Initialize some variables
face_locations = []
face_encodings = []
face_names = []
process_this_frame = True

while True:
    # Grab a single frame of video
    ret, frame = video_capture.read()

    # Only process every other frame of video to save time
    if process_this_frame:
        # Resize frame of video to 1/4 size for faster face recognition processing
        small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)

        # Convert the image from BGR color (which OpenCV uses) to RGB color (which face_recognition uses)
        rgb_small_frame = small_frame[:, :, ::-1]
        
        # Find all the faces and face encodings in the current frame of video
        face_locations = face_recognition.face_locations(rgb_small_frame)
        face_encodings = face_recognition.face_encodings(rgb_small_frame, face_locations)

        face_names = []
        for face_encoding in face_encodings:
            # See if the face is a match for the known face(s)
            matches = face_recognition.compare_faces(known_face_encodings, face_encoding)
            name = "Unknown"

            # # If a match was found in known_face_encodings, just use the first one.
            # if True in matches:
            #     first_match_index = matches.index(True)
            #     name = known_face_names[first_match_index]

            # Or instead, use the known face with the smallest distance to the new face
            face_distances = face_recognition.face_distance(known_face_encodings, face_encoding)
            best_match_index = np.argmin(face_distances)
            if matches[best_match_index]:
                name = known_face_names[best_match_index]

            face_names.append(name)

    process_this_frame = not process_this_frame


    # Display the results
    for (top, right, bottom, left), name in zip(face_locations, face_names):
        # Scale back up face locations since the frame we detected in was scaled to 1/4 size
        top *= 4
        right *= 4
        bottom *= 4
        left *= 4

        # Draw a box around the face
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)

        # Draw a label with a name below the face
        cv2.rectangle(frame, (left, bottom - 35), (right, bottom), (0, 0, 255), cv2.FILLED)
        font = cv2.FONT_HERSHEY_DUPLEX
        cv2.putText(frame, name, (left + 6, bottom - 6), font, 1.0, (255, 255, 255), 1)

    # Display the resulting image
    cv2.imshow('Video', frame)

    # Hit 'q' on the keyboard to quit!
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# Release handle to the webcam
video_capture.release()
cv2.destroyAllWindows()