System and method for access control using a plurality of images

A system for face recognition, comprising

• A. a camera,
• B. a plurality of scorers coupled to the camera and receiving therefrom a plurality of frames of a video stream imaging a candidate individual in a field of view of the camera,
• C. each scorer generating for each of the plurality of frames one or more scores of the respective frame and/or of the candidate individual imaged therein,
• D. a frame selector coupled to the scorers, the frame selector selecting fewer than all of the plurality of frames for matching by a face recognizer, where such selection is based on one or more scores of each respective frame,
• E. the face recognizer coupled to the frame selector and, if at least N frames selected in the selecting step have a score greater than or equal to a value k2, and if any of
• (a) at least M frames selected in the selecting step have a score greater than or equal to a value k1, and
• (b) if a designated time interval has passed since the candidate individual was first imaged in the frames,
• matching the candidate individual, as imaged in a plurality of said selected frames, against a set of one or more images of designated individuals, where k1<k2 and N<M and M>1,
• F. a controller that collects additional frames from the frame selector for application to the face recognizer if the face recognizer does not find a match between the candidate individual and a said designated individual, and if any of
• (a) the scores generated by the scorers are increasing, and
• (b) a closeness of match of the candidate individual imaged in the selected frames against the set of one or more designated individuals is increasing, and
• G. the system generating an output indicative of approval or denial of the candidate individual based on matching by the face recognizer.

A method of face recognition, comprising

• A. receiving a plurality of frames of a video stream imaging a candidate individual in a field of view of a camera,
• B. generating for each of the plurality of frames one or more scores of the frame and/or of the candidate individual imaged therein,
• C. selecting a target number of frames for matching by a face recognizer, where such selection is based on one or more of the scores of each respective frame,
• D. invoking the face recognizer on a plurality of the selected frames if at least N frames selected in the selecting step have a score greater than or equal to a value k2, and if any of
• (a) at least M frames selected in the selecting step have a score greater than or equal to a value k1, or
• (b) if a designated time interval has passed since the candidate individual was first imaged in the frames,
• where k1<k2 and N<M and M>1, where the invoking step includes invoking the face recognizer to match the candidate individual imaged in the plurality of selected frames against a set of one or more designated individuals,
• E. if, in the invoking step, the candidate individual does not match a said designated individual, and if any of
• (a) the scores generated in step (B) are increasing, and
• (b) a closeness of match of the candidate individual imaged in the selected frames against the set of one or more designated individuals is increasing,
• executing steps (A)-(D) to acquire, select and match additional frames, and
• F. generating an output indicative of approval or denial of the candidate individual based on said matching by the face recognizer.