Drowsiness Detection Using Cv2 In Python - Interesting Project - 2024

Hey guys in this blog we will build a Drowsiness Detection app that will detect if the person in the video is getting Drowsy or not.

This is a very interesting yet easy project with even less than 80 lines of code, so without any further due, let’s do it…

Table of Contents

Sneak at our Output

Code for Drowsiness Detection

from imutils import face_utils
import dlib
import cv2
from pygame import mixer

thres = 6

mixer.init()
sound = mixer.Sound('alarm.wav')

dlist = []

detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor("shape_predictor_68_face_landmarks.dat")

cap = cv2.VideoCapture(0)

def dist(a,b):
    x1,y1 = a
    x2,y2 = b
    return ((x1-x2)**2 + (y1-y2)**2)**0.5
 
while True:
    # Getting out image by webcam 
    _, image = cap.read()
    # Converting the image to gray scale
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
        
    # Get faces into webcam's image
    rects = detector(gray, 0)
    
    # For each detected face, find the landmark.
    for (i, rect) in enumerate(rects):
        # Make the prediction and transfom it to numpy array
        shape = predictor(gray, rect)
        shape = face_utils.shape_to_np(shape)
    
        # Draw on our image, all the finded cordinate points (x,y) 
        for (x, y) in shape:
            cv2.circle(image, (x, y), 2, (0, 255, 0), -1)
        
        le_38 = shape[37]
        le_39 = shape[38]
        le_41 = shape[40]
        le_42 = shape[41]

        re_44 = shape[43]
        re_45 = shape[44]
        re_47 = shape[46]
        re_48 = shape[47]
        

        dlist.append((dist(le_38,le_42)+dist(le_39,le_41)+dist(re_44,re_48)+dist(re_45,re_47))/4<thres)
        if len(dlist)>10:dlist.pop(0)

        # Drowsiness detected
        if sum(dlist)>=4:
            try:
                sound.play()
            except:
                pass
        else:
            try:
                sound.stop()
            except:
                pass
        
    # Show the image
    cv2.imshow("Output", image)
    
    if cv2.waitKey(5) & 0xFF == 27:
        break

cv2.destroyAllWindows()
cap.release()

Line 1-4: Importing required libraries.
Line 6: Setting a threshold (will see in the code ahead).
Line 8-9: Creating alarm sound using the pygame module to use it further in the app.
Line 11: An empty list that we will use ahead.
Line 13: Using dlib face detector.
Line 14: Using dlib landmarks detector to detect eye points.
Line 16: Initializing cap object to use Webcam later.
Line 18-21: A simple distance function that calculates the distance between two coordinates.
Line 25: Reading images from the webcam.
Line 27: Converting them to Grayscale.
Line 30: Detecting faces.
Line 33: Start traversing in those faces.
Lin 35-36: Get the 68 face landmarks and convert them to a NumPy array.
Line 39-40: Draw all the landmarks.
Line 42-50: Extract required eye landmarks.
- For the left eye, we will extract 38, 39, 42, and 41.
- For the right eye, we will extract 44, 45, 48, and 47.
- Read the algo below once before reading further steps.

Face Landmarks Detection Drowsiness Detection — 68 landmarks

Line 54: This line is responsible for keeping the size of dlist=10.
- Deletion is done from the front and addition is done in end.
- It’s like a queue system.
Line 57-66: Play the alarm, when there are at least 4 Trues in the dlist. Stop it when they are less than 4.
Line 69 – Show the Image.
Line 71-72: Stop the app when the user hits the ESC key.
Line 74-75: Close all cv2 windows and release the webcam.

Algo for detecting Drowsiness:

Find the distances between 38-42, 39-41, 44-48, and 45-47 landmarks and find the average of those 4.
If this average is greater than thres we defined initially, append/add a True in our dlist.
If our dlist contains 4 or more Trues, it means in continuous 4 frames, drowsiness is detected so play the alarm.
We have kept this concept of 4 or more because if we don’t do so, our program will play an alarm even when we blink which is False Positive.