# 以 OpenCV 實現人臉辨識

## 分類檔
- 正臉
- cascade_frontalface_default.xml
- windows 目錄
- C:\Users\User\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\cv2\data\haarcascade_frontalface_alt.xml
- C:\Users\nantochang\AppData\Local\Programs\Python\Python38\Lib\site-packages\cv2\data\haarcascade_frontalface_alt.xml
## Sample code

import cv2
PATH_HAARCASCAD_FRONTFACE_DEFAULT=(r"C:\Users\User\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache\local-packages\Python38\site-packages\cv2\data\haarcascade_frontalface_alt.xml")
vid_cam = cv2.VideoCapture(0)
face_detector = cv2.CascadeClassifier(PATH_HAARCASCAD_FRONTFACE_DEFAULT)

while(vid_cam.isOpened()):
    ret, image_frame = vid_cam.read()
    gray = cv2.cvtColor(image_frame, cv2.COLOR_BGR2GRAY)
    faces = face_detector.detectMultiScale(gray, 1.3, 5)

    for (x,y,w,h) in faces:
        cv2.rectangle(image_frame, (x,y), (x+w,y+h), (255,0,0), 2)
    
    cv2.imshow('frame', image_frame)
    
    if cv2.waitKey(100) & 0xFF == ord('q'):
        break

vid_cam.release()
cv2.destroyAllWindows()

###### tags: `鯉魚國小`