FaceEyeDetection.py

import numpy as np
import cv2
import os
os.chdir("/home/pi/opencv-3.4.1/data/haarcascades")
# multiple cascades: https://github.com/Itseez/opencv/tree/master/data/haarcascades
faceCascade = cv2.CascadeClassifier('/home/pi/opencv-3.4.1/data/haarcascades/haarcascade_frontalface_default.xml')
eyeCascade = cv2.CascadeClassifier('/home/pi/opencv-3.4.1/data/haarcascades/haarcascade_eye.xml')

cap = cv2.VideoCapture(0)
cap.set(3,640) # set Width
cap.set(4,480) # set Height

while True:
    ret, img = cap.read()
    img = cv2.flip(img, -1)
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.3,
        minNeighbors=5,
        minSize=(30, 30)
    )

    for (x,y,w,h) in faces:
        cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
        roi_gray = gray[y:y+h, x:x+w]
        roi_color = img[y:y+h, x:x+w]

        eyes = eyeCascade.detectMultiScale(
            roi_gray,
            scaleFactor= 1.5,
            minNeighbors=10,
            minSize=(5, 5),
            )

        for (ex, ey, ew, eh) in eyes:
            cv2.rectangle(roi_color, (ex, ey), (ex + ew, ey + eh), (0, 255, 0), 2)

        cv2.imshow('video', img)

    k = cv2.waitKey(30) & 0xff
    if k == 27: # press 'ESC' to quit
        break

cap.release()
cv2.destroyAllWindows()