python - OpenCV 错误 : Assertion faild in a simple face detection beginers code

Question

我开始学习如何使用 OpenCV 和面部检测。我正在关注以下代码示例:https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_objdetect/py_face_detection/py_face_detection.html#face-detection .

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

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

faces = face_cascade.detectMultiScale(gray, 1.3, 5)
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()

我一直得到这个:

Traceback (most recent call last):
  File "D:/Korisnici/Josipa/Desktop/CV/face_detection.py", line 10, in <module>
    faces = face_cascade.detectMultiScale(gray, 1.3, 5)
error: OpenCV(4.1.1) C:\projects\opencv-python\opencv\modules\objdetect\src\cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function 'cv::CascadeClassifier::detectMultiScale' 

我不知道我做错了什么。

Answer 1

您忘记将 haarcascade_frontalface_default.xml 和 haarcascade_eye.xml 文件复制到您的工作目录。

我认为您必须下载 OpenCV https://github.com/opencv/opencv首先，这些 XML 文件存储在 opencv/data/haarcascades/ 文件夹中。

为我工作: