I am trying to learn face detection in python-3.6 using cv2.

I follow the src given in a book.

I have already installed opencv-python(3.2.0) by pip

.xml and .jpg files are all in the same path with python code.

from numpy import *
import cv2face_cascade = cv2.CascadeClassifier("D:\\Python\\FaceDetec\\lbpcascade_frontalface.xml")img = cv2.imread("z1.jpg")
gary = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)faces = face_cascade.detectMultiScale(gray, 1.2, 3)
for(x, y, w, h) in faces:img2 = cv2.rectangle(img, (x, y), (x+w, y+h), (255, 255, 255), 2)roi_gray = gray[y:y+h, x:x+w]roi_color = img[y:y+h, x:x+w]cv2.imshow("img", img)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imwrite("z1.head.jpg", img)

I am getting an error to which I am not able to find anywhere.

OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage, file D:\Build\OpenCV\opencv-3.2.0\modules\core\src\persistence.cpp, l
ine 4422
Traceback (most recent call last):File "d:\Python\FaceDetec\Harr_cascade.py", line 6, in <module>face_cascade = cv2.CascadeClassifier("D:\\Python\\FaceDetec\\lbpcascade_frontalface.xml")
cv2.error: D:\Build\OpenCV\opencv-3.2.0\modules\core\src\persistence.cpp:4422: error: (-49) Input file is empty in function cvOpenFileStorage

Kindly help me in this. Thank you.

I have spent lot of manhours on this small trivial issue. The real issue is that Open CV will work only with the Haarcascade XML files, which are available on the Opencv.org website and not from the github