Accuracy in landmarks prediction using dlib

Question

I'm trying to find landmarks using dlib. So, I'm fitting my model with HELEN dataset, there are 2000 items downloaded from here. But accuracy is very very low. But when I use shape_predictor_68_face_landmarks.dat accuracy is high. I've read the Kazemi paper and set nu as 0.1, depth=4 and oversampling_amount=20, but it's still work badly. What's wrong?

Answer 1

Dlib landmark trainer uses default parameters if size of the dataset is large enough but bounding box for the detected face should be square. Since faces are almost symmetric, augmenting the dataset by flipping the images vertically may increase the accuracy.