face_image=image[top:bottom,left:right]

这段代码使用了Python中的切片操作，从原始图像中截取出了一个矩形区域，该区域的左上角坐标为(left, top)，右下角坐标为(right, bottom)。其中，top, bottom, left, right是人脸位置信息中的四个坐标值，image是原始图像。截取出的矩形区域存储在变量face_image中，可以用于后续的人脸识别或者人脸特征提取等任务。

相关问题

import cv2 import face_recognition import numpy as np from PIL import Image, ImageDraw,ImageFont video_capture = cv2.VideoCapture(r'C:/Users/ALIENWARE/123.mp4')#如果输入是(0)为摄像头输入 #现输入为MP4进行识别检测人脸 first_image = face_recognition.load_image_file("1.jpg") first_face_encoding = face_recognition.face_encodings(first_image)[0] Second_image = face_recognition.load_image_file("2.jpg") Second_face_encoding = face_recognition.face_encodings(Second_image)[0] third_image = face_recognition.load_image_file("3.jpg") third_face_encoding = face_recognition.face_encodings(third_image)[0] inside_face_encodings = [first_face_encoding,Second_face_encoding,third_face_encoding] inside_face_names = ['A','B','C'] face_locations = [] face_encodings = [] face_names = [] process_this_frame = True while True: ret, frame = video_capture.read() small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25) rgb_small_frame = small_frame[:, :, ::-1] if process_this_frame: 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: matches = face_recognition.compare_faces(inside_face_encodings, face_encoding) name = '未录入人脸' if True in matches: first_match_index = matches.index(True) name = inside_face_names[first_match_index] face_names.append(name) process_this_frame = not process_this_frame for (top, right, bottom, left), name in zip(face_locations, face_names): top *= 4 right *= 4 bottom *= 4 left *= 4 cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2) img_pil = Image.fromarray(frame) draw = ImageDraw.Draw(img_pil) fontStyle = ImageFont.truetype("C:/Windows/Fonts/simsun.ttc", 32, encoding="utf-8") draw.text((left + 6, bottom - 6), name, (0, 200, 0), font=fontStyle) frame = np.asarray(np.array(img_pil)) cv2.imshow('face_out', frame) if cv2.waitKey(1) & 0xFF == ord('q'): #退出需要按下Q键否则内核会崩溃 break video_capture.release() cv2.destroyAllWindows()

以下是修改后的代码，主要是添加了注释和一些规范化的修改：

import cv2
import face_recognition
import numpy as np
from PIL import Image, ImageDraw, ImageFont

# 加载要识别的人脸图片
first_image = face_recognition.load_image_file("1.jpg")
first_face_encoding = face_recognition.face_encodings(first_image)[0]

Second_image = face_recognition.load_image_file("2.jpg")
Second_face_encoding = face_recognition.face_encodings(Second_image)[0]

third_image = face_recognition.load_image_file("3.jpg")
third_face_encoding = face_recognition.face_encodings(third_image)[0]

# 存储要检测的人脸编码及对应的人名
inside_face_encodings = [first_face_encoding, Second_face_encoding, third_face_encoding]
inside_face_names = ['A', 'B', 'C']

# 打开视频流
video_capture = cv2.VideoCapture(r'C:/Users/ALIENWARE/123.mp4')

# 循环读取视频帧
while True:
    # 读取一帧
    ret, frame = video_capture.read()

    # 降低帧率，加快处理速度
    if not ret:
        break

    # 缩小图片尺寸，加快处理速度
    small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)
    rgb_small_frame = small_frame[:, :, ::-1]

    # 处理每一帧图片
    face_locations = face_recognition.face_locations(rgb_small_frame)
    face_encodings = face_recognition.face_encodings(rgb_small_frame, face_locations)
    face_names = []

    # 遍历每个检测到的人脸
    for face_encoding in face_encodings:
        # 比对人脸编码
        matches = face_recognition.compare_faces(inside_face_encodings, face_encoding)
        name = '未录入人脸'

        # 找到匹配的人脸
        if True in matches:
            first_match_index = matches.index(True)
            name = inside_face_names[first_match_index]
        face_names.append(name)

    # 在画面上标记人脸及名字
    for (top, right, bottom, left), name in zip(face_locations, face_names):
        # 将坐标放大4倍，因为之前缩小了4倍
        top *= 4
        right *= 4
        bottom *= 4
        left *= 4

        # 画出人脸框
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)

        # 添加名字
        img_pil = Image.fromarray(frame)
        draw = ImageDraw.Draw(img_pil)
        fontStyle = ImageFont.truetype("C:/Windows/Fonts/simsun.ttc", 32, encoding="utf-8")
        draw.text((left + 6, bottom - 6), name, (0, 200, 0), font=fontStyle)
        frame = np.asarray(np.array(img_pil))

    # 显示画面
    cv2.imshow('face_out', frame)

    # 按下q键退出程序
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 释放视频流
video_capture.release()

# 关闭所有窗口
cv2.destroyAllWindows()

import face_recognition import cv2 def compareFaces(known_image, name): known_face_encoding = face_recognition.face_encodings(known_image)[0] for i in range(len(face_locations)): # face_Locations的长度就代表有多少张脸 top1, right1, bottom1, left1 = face_locations[i] face_image = unknown_image[top1:bottom1, left1:right1] face_encoding = face_recognition.face_encodings(face_image) if face_encoding: result = {} matches = face_recognition.compare_faces([unknown_face_encodings[i]], known_face_encoding, tolerance=0.39) if True in matches: print('在未知图片中找到了已知面孔') result['face_encoding'] = face_encoding result['is_view'] = True result['location'] = face_locations[i] result['face_id'] = i + 1 result['face_name'] = name results.append(result) if result['is_view']: print('已知面孔匹配照片上的第{}张脸!!'.format(result['face_id'])) unknown_image = face_recognition.load_image_file('qt.jpg') known_image1 = face_recognition.load_image_file('cs.png') known_image2 = face_recognition.load_image_file('cs1.png') results = [] unknown_face_encodings = face_recognition.face_encodings(unknown_image) face_locations = face_recognition.face_locations(unknown_image) compareFaces(known_image1, 'cs') compareFaces(known_image2, 'cs1') view_faces = [i for i in results if i['is_view']] if len(view_faces) > 0: for view_face in view_faces: top, right, bottom, left = view_face['location'] start = (left, top) end = (right, bottom) cv2.rectangle(unknown_image, start, end, (0, 0, 255), thickness=2) font = cv2.FONT_HERSHEY_DUPLEX cv2.putText(unknown_image, view_face['face_name'], (left + 6, bottom + 16), font, 1.0, (255, 255, 255), thickness=1) cv2.imshow('windows', unknown_image) cv2.waitKey()

这段代码看起来是使用了 face_recognition 和 cv2 库来进行人脸比对和标记。它加载了一个未知的图片和两个已知的图片，然后通过 face_recognition 库提取出人脸的编码和位置。接着使用 compareFaces 函数来比对已知图片中的人脸和未知图片中的人脸，并将匹配结果保存在 results 列表中。最后，将匹配到的人脸在未知图片上用矩形框和文字标记出来，并显示在窗口中。

需要注意的是，这段代码中的路径和文件名是固定的，你可能需要根据实际情况修改。另外，由于我是文本 AI，并不能直接运行和显示图片，所以你需要在合适的环境中运行这段代码。