python - 使用 Haar 进行人脸检测 - OpenCV python

Question

我正在尝试这个 python 代码片段:

import numpy as np
import cv2

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

img = cv2.imread('img.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

faces = face_cascade.detectMultiScale(gray, 1.3, 3)
for (x,y,w,h) in faces:
    img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
    roi_gray = gray[y:y+h, x:x+w]
    roi_color = img[y:y+h, x:x+w]
    eyes = eye_cascade.detectMultiScale(roi_gray)
    for (ex,ey,ew,eh) in eyes:
        cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)

cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()

但是我得到这个错误:

Traceback (most recent call last):
  File "test.py", line 14, in <module>
    roi_color = img[y:y+h, x:x+w]
TypeError: 'NoneType' object has no attribute '__getitem__'

我找到了这个程序 here .

Answer 1

如果您确定您的图像路径是正确的，但问题仍然存在，请尝试这样做:

来自这一行

img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

去掉img =，就这样吧

cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)

这对我有用。