Dlib Error deserializing object of type unsigned long while deserializing object of type std::string

Question

I try to run a Python code for face detection using Dlib. But when I try to load the file shape_predictor_68_face_landmarks.dat using the following command face_detector =dlib.cnn_face_detection_model_v1('shape_predictor_68_face_landmarks.dat') I get the following error:

    Traceback (most recent call last):
  File "face_detector.py", line 6, in <module>
    face_detector = dlib.cnn_face_detection_model_v1('shape_predictor_68_face_landmarks.dat')
RuntimeError: An error occurred while trying to read the first object from the file shape_predictor_68_face_landmarks.dat.
ERROR: Error deserializing object of type unsigned long
   while deserializing object of type std::string

I have downloaded the shape predictor file from github: https://github.com/davisking/dlib-models

This is my Python code

import dlib
import cv2


face_detector = dlib.cnn_face_detection_model_v1('shape_predictor_68_face_landmarks.dat')

The rest of the code is omitted because it's not necessary

I am using: Ubuntu 18.04 and Python 3.6

UPDATE 1:

If use the same file with the function dlib.shape_predictor(shape_predictor_68_face_landmarks.dat) it runs without any problems!

It seems that there is a problem with the function dlib.cnn_face_detection_model_v1. Please correct me if I'm wrong!

Answer 1

I have contacted Davis King on twitter and he tshape_predictor_68_face_landmarks.dat is not the correct file. I have to load mmod_human_face_detector.dat file for function dlib.cnn_face_detection_model_v1()

It must be called like this

face_detector = dlib.cnn_face_detection_model_v1('mmod_human_face_detector.dat')