It sounds like you intend to associate facial images with other
personally identifiable information. Is that correct?
Not exactly? It depends on where you draw the system boundaries.
In the scope of the computer vision system I proposed earlier, that works with a single generic face detector that draws a rough box around each face. It doesn't know who each person is, nor anything about them.
Process inputs: video stream and camera parameters Process output: event sequence (face found, cropped face, face lost) stored in cropped video streams.
This phase isn't too different than having a human doing the cropping, except the computer doesn't know anyone, and a human might.
Associating faces or seats would probably be done somewhere outside of this processing pipeline though.