问题描述
我正在尝试使用 python 的“Open-CV”进行人脸检测。该程序向我抛出了一个错误,我作为 Python 初学者无法理解。 程序错误:
Traceback (most recent call last):
File "c:\Users\(User's name)\Documents\Python\Face-dection\Facedectection.py",line 6,in <module>
gray_img=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-wvn_it83\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion Failed) !_src.empty() in function 'cv::cvtColor'
代码:
import cv2
face_cascade=cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
img = cv2.imread("photo.jpg")
gray_img=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
faces=face_cascade.detectMultiScale(gray_img,scaleFactor=1.05,minNeighbors=5)
for x,y,w,h in faces:
img=cv2.rectangle(img,(x,y),(x+w,y+h),(0,255,0),3)
resized=cv2.resize(img,(int(img.shape[1]/3)),(int(img.shape[0]/3)))
cv2.imshow("Deteced-face",resized)
cv2.waitKey(0)
cv2.destroyAllWindows()
解决方法
您需要在引用 cv2.data.haarcascades
文件之前添加 .xml
。
#[...]
face_cascade=cv2.CascadeClassifier(cv2.data.haarcascades + "haarcascade_frontalface_default.xml") #Note the change
#[...]
你的代码还有一个问题,看看这段代码:
resized=cv2.resize(img,(int(img.shape[1]/3)),(int(img.shape[0]/3)))
你应该传递一个图像,它是新的宽度和高度(以元组格式)作为参数 但是您将图像以及宽度和高度作为单独的整数传递而不是在 元组格式。
它应该是这样的:
resized=cv2.resize(img,(int(img.shape[1]/3),int(img.shape[0]/3)))
'''
Notice I have removed an extra bracket after
cv2.resize(img,(int(img.shape[1]/3)) -> cv2.resize(img,(int(img.shape[1]/3)...
and also I have removed an extra bracket before
(int(img.shape[0]/3))) -> int(img.shape[0]/3)))
'''
这应该有效:
import cv2
face_cascade=cv2.CascadeClassifier(cv2.data.haarcascades + "haarcascade_frontalface_default.xml") #Note the change
img = cv2.imread("photo.jpg")
gray_img=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
faces=face_cascade.detectMultiScale(gray_img,scaleFactor=1.05,minNeighbors=5)
for x,y,w,h in faces:
img=cv2.rectangle(img,(x,y),(x+w,y+h),(0,255,0),3)
resized=cv2.resize(img,int(img.shape[0]/3)))
cv2.imshow("Deteced-face",resized)
cv2.waitKey(0)
cv2.destroyAllWindows()