python - 人脸检测抛出错误:函数 cv::CascadeClassifier::detectMultiScale 中的 !empty()

Question

我正在使用内置的级联分类器进行人脸检测。代码是这样的(OpenCV Python Tutorials):

import numpy as np
import cv2

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

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

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

for (x,y,w,h) in faces:
    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()

但是当我运行代码时出现以下错误:

C:\Python27\python.exe C:/Users/DELL/Downloads/Amma/code/fd.py

OpenCV Error: Assertion failed (!empty()) in cv::CascadeClassifier::detectMultiScale, file C:\builds\master_PackSlaveAddon-win32-vc12-static\opencv\modules\objdetect\src\cascadedetect.cpp, line 1634 Traceback (most recent call last): File "C:/Users/DELL/Downloads/Amma/code/fd.py", line 10, in faces = face_cascade.detectMultiScale(img, 1.3, 5) cv2.error: C:\builds\master_PackSlaveAddon-win32-vc12-static\opencv\modules\objdetect\src\cascadedetect.cpp:1634: error: (-215) !empty() in function cv::CascadeClassifier::detectMultiScale

Answer 1

引用this代码行，它无法检查级联是否为空。请使用训练有素的级联检查 XML 文件的路径。您可能需要像这样指定 XML 的完整路径:

face_cascade = cv2.CascadeClassifier('D:\opencv\data\haarcascades\haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('D:\opencv\data\haarcascades\haarcascade_eye.xml')

或者只是将这些文件放到包含您的脚本的目录中。