save "known people" face detection to local db or similar

• face_recognition version: 1.2.3
• Python version: 3.7
• Operating System: Debian 10.1

Description

face_detection need to scan "known_people" directory every time.
in "known_people" directory I've 20 people and face_detection need a lot of time to "learn" before search known peoples inside new photos (unknown_pictures directory contain 2 photos).
it's possible to cache "learn" analisys to emprove performances?

What I Did

# time face_recognition --cpus 4 ./known_people/ ./unknown_pictures/
WARNING: More than one face found in ./known_people/fenice_felce.jpg. Only considering the first face.
./unknown_pictures/01.jpg,formica_coriandolo
./unknown_pictures/01.jpg,formica_coriandolo
./unknown_pictures/01.jpg,iora_lenticchia
./unknown_pictures/02.jpg,unknown_person
./unknown_pictures/02.jpg,unknown_person
./unknown_pictures/02.jpg,cervo_volante_ginepro
./unknown_pictures/02.jpg,formica_coriandolo
./unknown_pictures/02.jpg,iora_lenticchia
./unknown_pictures/02.jpg,unknown_person
./unknown_pictures/02.jpg,formichiere_carota

real    0m48,144s
user    0m41,635s
sys     0m2,683s

Start by reviewing the face_recognition command path used with the known_people and unknown_pictures directories, focusing on where known faces are learned. Determine how reusable local data could avoid rescanning known_people while remaining valid when that directory changes. Done means repeated searches no longer redo unchanged learning and still produce correct recognition results.