How can i recognize A strange face ?

[1123311314]

If I give a strange face (not in Training data ) , this app return an error name .
How can I separate this face is not in the data sample , or similarity degree

[wihoho]

You need to setup some threshold. If the strange face produces a large threshold, you need to return an error saying that this face is not in the training set.

[1123311314]

Oh , in this case. Can you give me some reference to set the threshold , or some example.
I will try it again ,thanks

[wihoho]

This is the uncertainty in machine learning. You need to justify a threshold on your own based on your own requirements.