filter.py

import cv2 as cv #pip install opencv-python
import argparse

#Code from OPENCV docs: https://docs.opencv.org/3.4/db/d28/tutorial_cascade_classifier.html 

def detectAndDisplay(frame, face_cascade, eyes_cascade):
    frame_gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
    frame_gray = cv.equalizeHist(frame_gray)
    #-- Detect faces
    faces = face_cascade.detectMultiScale(frame_gray)
    for (x,y,w,h) in faces:
        center = (x + w//2, y + h//2)
        frame = cv.ellipse(frame, center, (w//2, h//2), 0, 0, 360, (255, 0, 255), 4)
        faceROI = frame_gray[y:y+h,x:x+w]
        #-- In each face, detect eyes
        eyes = eyes_cascade.detectMultiScale(faceROI)
        for (x2,y2,w2,h2) in eyes:
            eye_center = (x + x2 + w2//2, y + y2 + h2//2)
            radius = int(round((w2 + h2)*0.25))
            frame = cv.circle(frame, eye_center, radius, (255, 0, 0 ), 4)
    cv.imshow('Capture - Face detection', frame)

def setup_args():
    parser = argparse.ArgumentParser(description='Code for Cascade Classifier tutorial.')
    parser.add_argument('--face_cascade', help='Path to face cascade.', default='data/haarcascades/haarcascade_frontalface_alt.xml')
    parser.add_argument('--eyes_cascade', help='Path to eyes cascade.', default='data/haarcascades/haarcascade_eye_tree_eyeglasses.xml')
    parser.add_argument('--camera', help='Camera divide number.', type=int, default=0)
    args = parser.parse_args()
    return args


def main():
    args = setup_args()
    face_cascade_name = args.face_cascade
    eyes_cascade_name = args.eyes_cascade

    face_cascade = cv.CascadeClassifier()
    eyes_cascade = cv.CascadeClassifier()
    #-- 1. Load the cascades
    if not face_cascade.load(face_cascade_name):
        print('--(!)Error loading face cascade')
        exit(0)
    if not eyes_cascade.load(eyes_cascade_name):
        print('--(!)Error loading eyes cascade')
        exit(0)
    camera_device = args.camera
    #-- 2. Read the video stream
    cap = cv.VideoCapture(camera_device)
    if not cap.isOpened:
        print('--(!)Error opening video capture')
        exit(0)
    while True:
        ret, frame = cap.read()
        if frame is None:
            print('--(!) No captured frame -- Break!')
            break
        detectAndDisplay(frame, face_cascade, eyes_cascade)
        if cv.waitKey(10) == 27:
            break

if __name__ == "__main__":
    main()