opencv FaceRecognition during login
You can store the snapshots in an array, run your recognition on each image and see if the user is recognized as one of the users you have trained your model on.
If not then prompt the user for their name, if the name matches one of the users you trained your model on, add these snapshots to their training set and re-train, so the model is more up to date, if it does not match any names, then you assume this is a new user and create a new label and folder for them, and retrain your recognizer.
Beware though that each time you add more snapshots the training time will increase, so perhaps limit each snapshot capture to 1 FPS or something.
maybe some of you can point me in the right direction.
I've been playing around with OpenCV FaceRecognition for some time with Eigenfaces to let it learn to recognize faces. Now I would like to let it run during windows logon. 
Precisely, I want to make Snapshots of Faces when I log into a user so after the software has learned the faces after x logins and to which user it belongs, it will log me in automatically when it recognises me during typing. 
As a prototype it would be enough to somehow get a textfield and get textinput working to "simulate" login in. Im using python.
I hope you understand what i want to achieve and can help me out.
Edit: Another Question/Idea: If i want to build an Application in Visual Studio, can I reuse my python Code or do I have to use c++? I could make a Windows Store app or something like that.