main.py

#!/usr/bin/env python
import cv2 as cv

upper = cv.CascadeClassifier("haarcascade_upperbody.xml")
body = cv.CascadeClassifier("haarcascade_fullbody.xml")
face = cv.CascadeClassifier("haarcascade_frontalface_default.xml")
smile  = cv.CascadeClassifier("haarcascade_smile.xml")

def detect(cascade, frame):
    return cascade.detectMultiScale(gray, 1.3, 5)

def drawn(frame, entities, color, thickness):
    (r, g, b) = color
    for (x, y, w, h) in entities:
        cv.rectangle(frame, (x, y), (x+w, y+h), (r, g, b), thickness)

cam = cv.VideoCapture(0)
while True:
    ret, frame = cam.read()
    gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
    
    bodies = detect(body, gray)
    drawn(frame, bodies, (0, 255, 0), 2)

    uppers = detect(upper, gray)
    drawn(frame, uppers, (255, 0, 0), 2)


    faces = detect(face, gray)
    drawn(frame, faces, (255, 0, 255), 2)

    smiles = detect(smile, gray)
    drawn(frame, smiles, (255, 0, 255), 2)

    cv.imshow('frame', frame)
    if cv.waitKey(1) & 0xFF == ord('q'):
        break

cam.release()
cv.destroyAllWindows()