import cv2

faceCascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

cap = cv2.VideoCapture(0)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)

while True:
    ret, frame = cap.read()
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    faces = faceCascade.detectMultiScale(gray, scaleFactor = 1.1, minNeighbors = 5, minSize = (30, 30))
    print('人臉數:', len(faces))

    for (x, y, w, h) in faces:
        frame = cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 3)
        face_rect = gray[y:y + h, x:x + w]
        eyes = eye_cascade.detectMultiScale(face_rect, 1.3, 8)

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

    cv2.imshow('preview', frame)

    if cv2.waitKey(1) == 27:
        break

cap.release()
cv2.destroyAllWindows()