Realtime face detection on web cam in Python using OpenCV

Open CV

Open CV is a powerful library that helps you in implementing many features like Automatic face detection , changing images to grayscale,image rotation and many more features related to images and videos. So here we will be using this for face detection on webcam realtime.

So we will add new python file and name it facedetection.py

Now copy the following piece of code for face detection

import cv2
import sys
from time import sleep

cascPath = "haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascPath)


video_capture = cv2.VideoCapture(0)
anterior = 0

while True:
    if not video_capture.isOpened():
        print('Unable to load camera.')
        sleep(5)
        pass

    # Capture frame-by-frame
    ret, frame = video_capture.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.1,
        minNeighbors=5,
        minSize=(30, 30)
    )

    # Draw a rectangle around the faces
    for i,(x, y, w, h) in enumerate(faces):
        cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
        face = frame[y:y+h, x:x+w]
        cv2.imwrite(f'face{i}.jpg', face)
        

    if anterior != len(faces):
        anterior = len(faces)
        


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


    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

    # Display the resulting frame
    cv2.imshow('Video', frame)
    
# When everything is done, release the capture
video_capture.release()
cv2.destroyAllWindows()

Now save the file and open the command prompt and go to the location of file. Here first we have to install two packages.Run following command and press enter

pip install opencv-python==4.6.0.66

It will look like in the image below

Now install this second package 

pip install opencv-contrib-python

You can check the command in below image

We this you will also need to add one xml file in the same location as your program. You can see the file in the image below You can download the files from the download button above.Now run the program and it will open the webcam on your system

You will be able to see the rectangle drawn on your webcam detecting your face. it will also save the detected face in the same location with name face0.jpg

So this is how we can implement realtime face detection on web cam in Python using OpenCV.