调用OpenCV的detectMultiScale()函数时出现Bad Argument错误求助

你的问题核心是参数拼写错误，报错信息已明确提示：'minNeighbours' is an invalid keyword argument，原因是OpenCV的detectMultiScale()参数采用美式英语拼写，正确参数名是minNeighbors（去掉中间的字母u），而非英式拼写的minNeighbours。

修正后的代码 #

import cv2 as cv
img=cv.imread('photo/goku3.jpg')
cv.imshow('image', img)

gray=cv.cvtColor(img, cv.COLOR_BGR2GRAY)
cv.imshow('gray', gray)

haar_cascade=cv.CascadeClassifier('faces.xml')
# 修正参数拼写：minNeighbours → minNeighbors
faces_rect=haar_cascade.detectMultiScale(gray, scaleFactor=1.1, minNeighbors=3)
print(f"Number of faces found = {len(faces_rect)}")

for (x,y,w,h) in faces_rect:
    cv.rectangle(img, (x,y), (x+w,y+h), (0,255,0), thickness=2)

cv.imshow('detected face', img)
cv.waitKey(0)

补充说明 #

• 该错误与detectMultiScale()函数可用性无关，无需重装OpenCV
• OpenCV的Python接口参数命名普遍遵循美式英语规则，遇到参数错误时优先检查拼写是否符合官方规范

内容的提问来源于stack exchange，提问作者Parth Parlikar