Face, Eye and Smile detector in OpenCV

smile_detector.py

import cv2

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') # Load the cascade for the face.
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml') # Load the cascade for eye
smile_cascade = cv2.CascadeClassifier('haarcascade_smile.xml') # Load the cascade for smile


def detect(gray, frame):
    faces = face_cascade.detectMultiScale(gray, 1.3, 5)
    for x,y,w,h in faces:
        cv2.rectangle(frame, (x,y), (x+w, y+h), (255,0,0), 2)
        roi_gray = gray[y:y+h, x:x+w]
        roi_color = frame[y:y+h, x:x+w]
        eyes = eye_cascade.detectMultiScale(roi_gray, 1.1, 5)
        for ex,ey,ew,eh in eyes:
            cv2.rectangle(roi_color, (ex,ey), (ex+ew,ey+eh), (0,255,0), 2)
        smiles = smile_cascade.detectMultiScale(roi_gray, 1.7, 22)
        for sx,sy,sw,sh in smiles:
            cv2.rectangle(roi_color, (sx,sy), (sx+sw,sy+sh), (0,0,255), 2)
    return frame

video_capture = cv2.VideoCapture(0)

if video_capture.isOpened():
    while True:
        ret, frame = video_capture.read()
        if ret:
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            canvas = detect(gray, frame)
            cv2.imshow('Video', canvas)
            if cv2.waitKey(1) & 0xFF== ord('q'):
                break
        else:
            print("Video not going on")
            break

video_capture.release()
cv2.destroyAllWindows()