Automated recognition of faces that change over time

A system for access control comprising

• A. one or more nodes, each of which nodes includes a camera and an associated processing device, and each of which nodes performs facial recognition on individuals imaged by its respective camera and, based thereon, generates messaging and/or control signals to permit or deny access to a resource secured by that node,
• B. a server that is in communications coupling with the nodes and that includes a central store of facial images of known individuals,
• C. at least a given one of said nodes including a respective local store representing at least some of the facial images in the central store and performing said facial recognition using the images so represented in that respective local store,
• D. if such facial recognition identifies a match between an individual in an image acquired by the camera of the given node and a facial image of a said known individual represented in the local store of that node, that node determining whether that camera-acquired image is a candidate to update a facial image of that known individual in the central store and, if so, uploading that camera-acquired image to the server, where such determination is based on numerical or other characterizations of a quality of the camera-acquired image and a face depicted therein,
• E. the server selecting a candidate image received from the given node for actual inclusion in the central store to update the facial image of the known individual in that image based on a mathematical relation of values of F1, a measure of the quality of that candidate image;
• F2, a measure of the degree of similarity of the face in that candidate image and a said facial image of a known individual in the central store;
• and F3, a measure of the degree to which the face in the candidate image reflects a permissible or expected change in that known individual,
• wherein the permissible or expected change in the known individual is a change such as aging, weight gain/loss, changes or addition of eyewear, changes in facial ornamentation such as facial hair, tattoos, and jewelry.