Patent ID: 8957956
Filing Date: 2015-02-17
Classification: H04N

Abstract:
1. A process to capture an image of a subject's iris, wherein the subject has a head and at least one eye including the iris, the head of the subject positioned within an imaging space including three-dimensional volume forming an operating range, the operating range having a near-end plane and a far-end plane, wherein the subject's eye is facing toward the near-end plane of the imaging space, the process comprising: using a camera to capture a sequence of illuminated images of the subject's head, wherein the images comprise a plurality of frames and are stored in a data storage device for later processing to identify the subject by comparing at least one feature of the subject's iris to iris features of known subjects stored in a database; dynamically changing the focus point for each image captured by moving the camera so that the focus point sweeps in discrete steps through the operating range so that successive images have overlapping depths of field so that the iris of the subject is within at least one of the depths of field corresponding to a particular image, wherein the camera moves at a constant velocity through the operating range and captures the sequence of illuminated images at increasingly longer time intervals, or the camera moves at an increasing velocity through the operating range and captures the sequence of illuminated images using a constant frame period; wherein the image containing the iris of the eye of the subject may be associated with any one of the images within the operating range; further wherein the operating range and overlapping depths of field provide that the at least one image containing the iris is focused on the iris of the eye of the subject; further wherein at least one image in the operating range contains an image of the iris substantially in focus and useful for identifying the subject using the at least one image of the iris; and processing the at least one image of the iris to identify the subject.