[cortesoft]

If the system sees someone exit a building and that person does not match someone the system saw enter the building, the person could be flagged and tracked as possibly being someone else who entered the building. Once the system accounts for everyone else who entered the building (by seeing when they exit), the system would be able to correlate that the unknown person who exited is the same as the only unaccounted for person who exited

[dylan604]

If that building in an apartment building? Someone from an apartment building might not enter before leaving on the same day. How far back in the camera's history does the system look for that person entering?

[cortesoft]

This is the point... computers can watch 24/7 and never forget or get distracted. The system could look weeks back, and will never forget a person.

[BobaFloutist]

I know storage is cheap, but I think you run into storage space issues very rapidly if you want high-definition, 24/7 surveillance of every apartment building stretching back weeks.

[mywrathacademia]

Storing video footage from weeks back does not seem feasible. I assume footage would get overwritten after a specific time period.

[cortesoft]

It doesn’t need to store video, just data about where the person is and there various identifying data… the system uses the recordings to generate fingerprints for everyone, then just stores data about where you were/are.

[Symbiote]

Store hashes of the detected faces. Or store low framerate video, just occasional frames where people are detected

[dylan604]

until someone finds that certain cameras are unavailable, or that something has obstructed the view for a significant enough time to cause reasonable doubt

[ndsipa_pomu]

Plastic surgery clinics would likely have an issue