Opencv项目实战:基于dlib的疲劳检测

一、项目简介

本项目基于dlib库提供的人脸检测器关键点定位工具以及眼睛纵横比算法完成。通过分析摄像头或视频流中的人脸,实时计算眼睛纵横比EAR(Eye Aspect Ratio),以判断眼睛是否闭合。通过统计眨眼次数,可以检测出眨眼的频率和时长,用于评估用户的注意力水平或疲劳状态

二、算法原理

论文地址:https://vision.fe.uni-lj.si/cvww2016/proceedings/papers/05.pdf

在这里插入图片描述

  • 由于眨眼动作是一个过程,而不是一个帧图像就能瞬间完成。故设置连续帧数的阈值(=3),即连续三帧图像计算得到的EAR值都小于EAR的阈值(=3),则表示眨眼一次。
  • 眨眼检测与疲劳检测的区别就是连续帧数的阈值设置,原理相同!

三、环境配置

dlib库在计算机视觉和人工智能领域有广泛的应用,包括人脸识别、人脸表情分析、人脸关键点检测、物体检测和追踪等任务。它的简单易用性、高性能和丰富的功能使其成为研究人员和开发者的首选库之一。

3.1、dlib人脸检测器:dlib.get_frontal_face_detector()

dlib官方详细说明:dlib.get_frontal_face_detector()

3.2、dlib关键点定位工具:shape_predictor_68_face_landmarks.dat

dlib官方预训练工具的下载地址:http://dlib.net/files/
(1)5个关键点检测:shape_predictor_5_face_landmarks.dat。五个点分别为:左右眼 + 鼻子 + 左右嘴角
(2)68个关键点检测:shape_predictor_68_face_landmarks.dat

脸部关键点注释详细请看:https://ibug.doc.ic.ac.uk/resources/facial-point-annotations/
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四、项目实战(加载视频)

  • 【参数配置】方式一:Pycharm + Terminal + 输入指令自动检测:python detect_blinks.py --shape-predictor shape_predictor_68_face_landmarks.dat --video test.mp4
  • 【参数配置】方式二:Pycharm + 点击Edit Configuration,输入配置参数--shape-predictor shape_predictor_68_face_landmarks.dat --video test.mp4,点击Run开始检测。

在这里插入图片描述

# 导入所需库
from scipy.spatial import distance as dist
from collections import OrderedDict
import numpy as np
import argparse
import time
import dlib
import cv2

# 定义脸部关键点索引
FACIAL_LANDMARKS_68_IDXS = OrderedDict([
    ("mouth", (48, 68)),
    ("right_eyebrow", (17, 22)),
    ("left_eyebrow", (22, 27)),
    ("right_eye", (36, 42)),
    ("left_eye", (42, 48)),
    ("nose", (27, 36)),
    ("jaw", (0, 17))
])


# 计算眼睛纵横比函数
def eye_aspect_ratio(eye):
    # 计算垂直距离
    A = dist.euclidean(eye[1], eye[5])
    B = dist.euclidean(eye[2], eye[4])
    # 计算水平距离
    C = dist.euclidean(eye[0], eye[3])
    # 计算眼睛纵横比EAR
    ear = (A + B) / (2.0 * C)
    return ear


# 解析命令行参数
ap = argparse.ArgumentParser()
ap.add_argument("-p", "--shape-predictor", required=True, help="面部地标预测器路径")
ap.add_argument("-v", "--video", type=str, default="", help="输入视频文件路径")
args = vars(ap.parse_args())

# 设置EAR阈值和连续帧数
EYE_AR_THRESH = 0.3
EYE_AR_CONSEC_FRAMES = 3

# 初始化计数器
COUNTER = 0		# 计算连续帧数3
TOTAL = 0		# 若连续帧数==3,则总眨眼次数+1

# 加载面部地标预测器
print("[INFO] 正在加载面部地标预测器...")
detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor(args["shape_predictor"])

# 分别获取左眼和右眼坐标索引
(lStart, lEnd) = FACIAL_LANDMARKS_68_IDXS["left_eye"]
(rStart, rEnd) = FACIAL_LANDMARKS_68_IDXS["right_eye"]

# 读取视频
print("[INFO] 开始视频流...")
vs = cv2.VideoCapture(args["video"])
time.sleep(1.0)


# 将shape对象转换为numpy数组
def shape_to_np(shape, dtype="int"):
    # 创建一个dtype类型的空ndarray用于存储68个关键点的坐标
    coords = np.zeros((shape.num_parts, 2), dtype=dtype)
    # 遍历每个关键点,提取坐标并存储到ndarray中
    for i in range(0, shape.num_parts):
        coords[i] = (shape.part(i).x, shape.part(i).y)
    return coords


# 不断循环处理每一帧图像
while True:
    # 预处理
    frame = vs.read()[1]
    if frame is None:
        break

    # 调整图像大小
    (h, w) = frame.shape[:2]
    width = 1200		# 脸部大小会影响检测器的识别,太小可能会识别不到
    r = width / float(w)
    dim = (width, int(h * r))
    frame = cv2.resize(frame, dim, interpolation=cv2.INTER_AREA)
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    # 人脸检测
    rects = detector(gray, 0)

    # 遍历检测到的每个人脸
    for rect in rects:
        # 获取关键点坐标
        shape = predictor(gray, rect)
        shape = shape_to_np(shape)

        # 提取左眼和右眼区域坐标
        leftEye = shape[lStart:lEnd]
        rightEye = shape[rStart:rEnd]

        # 计算左右眼纵横比EAR
        leftEAR = eye_aspect_ratio(leftEye)
        rightEAR = eye_aspect_ratio(rightEye)

        # 计算平均纵横比
        ear = (leftEAR + rightEAR) / 2.0

        # 绘制眼睛区域轮廓(凸包)
        leftEyeHull = cv2.convexHull(leftEye)
        rightEyeHull = cv2.convexHull(rightEye)
        cv2.drawContours(frame, [leftEyeHull], -1, (0, 255, 0), 1)
        cv2.drawContours(frame, [rightEyeHull], -1, (0, 255, 0), 1)

        # 检查是否满足EAR阈值
        if ear < EYE_AR_THRESH:
            COUNTER += 1
        else:
            # 如果连续几帧都是闭眼的,增加总数
            if COUNTER >= EYE_AR_CONSEC_FRAMES:
                TOTAL += 1
            # 重置计数器
            COUNTER = 0

        # 在图像中,显示眨眼次数和纵横比
        cv2.putText(frame, "Blinks: {}".format(TOTAL), (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)
        cv2.putText(frame, "EAR: {:.2f}".format(ear), (300, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)

    # 显示当前帧图像
    cv2.imshow("Frame", frame)
    key = cv2.waitKey(10) & 0xFF

    # 按下Esc键退出循环
    if key == 27:
        break


vs.release()				# 释放视频流
cv2.destroyAllWindows()		# 关闭所有窗口

五、项目实战(摄像头获取帧图像)

  • 【参数配置】方式一:Pycharm + Terminal + 输入指令自动检测:python detect_blinks.py --shape-predictor shape_predictor_68_face_landmarks.dat
  • 【参数配置】方式二:Pycharm + 点击Edit Configuration,输入配置参数--shape-predictor shape_predictor_68_face_landmarks.dat,点击Run开始检测。
# 导入所需库
from scipy.spatial import distance as dist
from collections import OrderedDict
import numpy as np
import argparse
import time
import dlib
import cv2

# 定义脸部关键点索引
FACIAL_LANDMARKS_68_IDXS = OrderedDict([
    ("mouth", (48, 68)),
    ("right_eyebrow", (17, 22)),
    ("left_eyebrow", (22, 27)),
    ("right_eye", (36, 42)),
    ("left_eye", (42, 48)),
    ("nose", (27, 36)),
    ("jaw", (0, 17))
])


# 计算眼睛纵横比函数
def eye_aspect_ratio(eye):
    # 计算垂直距离
    A = dist.euclidean(eye[1], eye[5])
    B = dist.euclidean(eye[2], eye[4])
    # 计算水平距离
    C = dist.euclidean(eye[0], eye[3])
    # 计算眼睛纵横比EAR
    ear = (A + B) / (2.0 * C)
    return ear


# 解析命令行参数
ap = argparse.ArgumentParser()
ap.add_argument("-p", "--shape-predictor", required=True, help="面部地标预测器路径")
args = vars(ap.parse_args())

# 设置EAR阈值和连续帧数
EYE_AR_THRESH = 0.3
EYE_AR_CONSEC_FRAMES = 3

# 初始化计数器
COUNTER = 0    # 计算连续帧数3
TOTAL = 0    # 若连续帧数==3,则总眨眼次数+1

# 加载面部地标预测器
print("[INFO] 正在加载面部地标预测器...")
detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor(args["shape_predictor"])

# 分别获取左眼和右眼坐标索引
(lStart, lEnd) = FACIAL_LANDMARKS_68_IDXS["left_eye"]
(rStart, rEnd) = FACIAL_LANDMARKS_68_IDXS["right_eye"]

# 读取视频
print("[INFO] 开始视频流...")
vs = cv2.VideoCapture(0)
time.sleep(1.0)

# 将shape对象转换为numpy数组
def shape_to_np(shape, dtype="int"):
    # 创建一个dtype类型的空ndarray用于存储68个关键点的坐标
    coords = np.zeros((shape.num_parts, 2), dtype=dtype)
    # 遍历每个关键点,提取坐标并存储到ndarray中
    for i in range(0, shape.num_parts):
        coords[i] = (shape.part(i).x, shape.part(i).y)
    return coords

# 不断循环处理每一帧图像
while True:
    # 预处理
    ret, frame = vs.read()
    if not ret:
        break

    # 调整图像大小
    (h, w) = frame.shape[:2]
    width = 1200    # 脸部大小会影响检测器的识别,太小可能会识别不到
    r = width / float(w)
    dim = (width, int(h * r))
    frame = cv2.resize(frame, dim, interpolation=cv2.INTER_AREA)
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    # 人脸检测
    rects = detector(gray, 0)

    # 遍历检测到的每个人脸
    for rect in rects:
        # 获取关键点坐标
        shape = predictor(gray, rect)
        shape = shape_to_np(shape)

        # 提取左眼和右眼区域坐标
        leftEye = shape[lStart:lEnd]
        rightEye = shape[rStart:rEnd]

        # 计算左右眼纵横比EAR
        leftEAR = eye_aspect_ratio(leftEye)
        rightEAR = eye_aspect_ratio(rightEye)

        # 计算平均纵横比
        ear = (leftEAR + rightEAR) / 2.0

        # 绘制眼睛区域轮廓(凸包)
        leftEyeHull = cv2.convexHull(leftEye)
        rightEyeHull = cv2.convexHull(rightEye)
        cv2.drawContours(frame, [leftEyeHull], -1, (0, 255, 0), 1)
        cv2.drawContours(frame, [rightEyeHull], -1, (0, 255, 0), 1)

        # 检查是否满足EAR阈值
        if ear < EYE_AR_THRESH:
            COUNTER += 1
        else:
            # 如果连续几帧都是闭眼的,增加总数
            if COUNTER >= EYE_AR_CONSEC_FRAMES:
                TOTAL += 1
            # 重置计数器
            COUNTER = 0

        # 在图像中,显示眨眼次数和纵横比
        cv2.putText(frame, "Blinks: {}".format(TOTAL), (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)
        cv2.putText(frame, "EAR: {:.2f}".format(ear), (300, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)

    # 显示当前帧图像
    cv2.imshow("Frame", frame)
    key = cv2.waitKey(1) & 0xFF

    # 按下Esc键退出循环
    if key == 27:
        break


vs.release()             # 释放视频流
cv2.destroyAllWindows()     # 关闭所有窗口

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转载自blog.csdn.net/shinuone/article/details/131097047
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