PERCLOS python代码

PERCLOS是通过检测眼睛的闭合程度来评估疲劳程度的指标。下面是一个使用Python实现PERCLOS的示例代码：

import dlib
import cv2
from scipy.spatial import distance as dist

def eye_aspect_ratio(eye):
    A = dist.euclidean(eye[1], eye[5])
    B = dist.euclidean(eye[2], eye[4])
    C = dist.euclidean(eye[0], eye[3])
    ear = (A + B) / (2.0 * C)
    return ear

detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor('shape_predictor_68_face_landmarks.dat')
cap = cv2.VideoCapture(0)

while True:
    ret, frame = cap.read()
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    rects = detector(gray, 0)

    for rect in rects:
        shape = predictor(gray, rect)
        shape = shape_to_np(shape)
        leftEye = shape[42:48]
        rightEye = shape[36:42]
        leftEAR = eye_aspect_ratio(leftEye)
        rightEAR = eye_aspect_ratio(rightEye)
        PERCLOS = (leftEAR + rightEAR) / 2
        cv2.putText(frame, "PERCLOS: {:.2f}".format(PERCLOS), (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 255), 2)

    cv2.imshow("Frame", frame)
    key = cv2.waitKey(1) & 0xFF
    if key == ord("q"):
        break

cap.release()
cv2.destroyAllWindows()

这段代码使用dlib库检测人脸和眼睛，计算左右眼的EAR（眼睛长宽比），然后计算PERCLOS并将其显示在视频流中。请注意，这段代码需要下载shape_predictor_68_face_landmarks.dat文件并将其放入与代码相同的目录中。