detecion on small faces

[Tetsujinfr]

hi, first thanks for the repo, the perf on jetson is quite remarkable. really cool.

I am trying to run the face detection on small faces, and I struggle to get good results.

I saw there were interesting parameters in mtcnn.cpp like the below lines:

int minsize = 60; 
int MIN_DET_SIZE = 12;

I have tried different values but the results are not intuitive and usually there are really bad (most detections disappear even for very large and clear faces).

Any advice on how to get better results on smaller faces in images?

thanks
edit: below an example with the default min size values unchanged: