Face recognition

https://github.com/ageitgey/face_recognition
https://github.com/oarriaga/face_classification
https://github.com/facebookresearch/faiss

dlib + CPU
sudo pip uninstall dlib
install dlib usinghttps://gist.github.com/ageitgey/629d75c1baac34dfa5ca2a1928a7aeaf with
python setup.py install --no DLIB_USE_CUDA

== to speedup ==
https://towardsdatascience.com/heres-how-you-can-get-a-2-6x-speed-up-on-your-data-pre-processing-with-python-847887e63be5