dlib_face_landmark_detection need 2 parameters

[almirb]

Hello,

I tried to use HOG to get the face descriptor, but without success. When I run the code below:

<?php

// face landmark detection
$landmarks = dlib_face_landmark_detection("~/a.jpg");
var_dump($landmarks);

I get the message: PHP Warning: dlib_face_landmark_detection() expects exactly 2 parameters, 1 given in /var/www/html/pdlib/face_test.php

Could you write an complete example to get the descriptor using HOG?

P.S.: Until now, I was using this Python api https://github.com/ageitgey/face_recognition with a local webservice to get the face descriptors. It usually takes 0.44 seconds. Using PDlib with CNN detection, I take more than 20 seconds to get the 128D descriptors. What am I doing wrong? Is that only a CNN x HOG difference?

Thanks!