opencv on cli by raspi camera module

face_detect.py

import cv2
import sys
import os

cascade_path = os.path.join(os.path.dirname(__file__),'haarcascade_frontalface_default.xml')
face_cascade = cv2.CascadeClassifier(cascade_path)

def detect_face(cap):
    while(cap.isOpened()):
        ret, frame = cap.read()
        frame = cv2.flip(frame, -1) #カメラ上下左右反転
        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
        faces = face_cascade.detectMultiScale(
            gray,
            scaleFactor=1.2,
            minNeighbors=5,
            #minSize=(20, 20)
        )
        if len(faces) > 0:
            break
    else:
        cap.release()
        #sys.exit(1)

def main():
    while(True):
        cap = cv2.VideoCapture(0)
        detect_face(cap)
        print('hit! face!')

        cap.release()

if __name__ == '__main__':
    main()