Image sensor with integrated region of interest calculation for iris capture, autofocus, and gain control

摘要

An iris recognition system and method for operating same is disclosed. The iris recognition system includes an image sensor, a buffer, a comparator, autofocus logic, and gain control logic. The image sensor is configured to obtain at least one image from a camera. The buffer communicatively connected to the image sensor stores values associated with the pixels in the image sensor. The comparator communicatively connected to the buffer obtains a coarse segmentation of an iris of a subject. The autofocus logic for adjusts the focus of a lens associated with the camera. The gain control logic adjusts the gain of the image sensor. The functions of obtaining a coarse segmentation, adjusting the focus of the lens, and adjusting the gain are based on the locations of the pixels with the highest value in the image sensor as stored in the buffer.

主权项

1. A method for locating and identifying an iris in an image taken by a camera associated with an iris recognition system comprising an image sensor and a plurality of illuminators, comprising the steps of:
illuminating a subject; capturing at least one image of the subject wherein the image comprises a plurality of pixels; determining a brightness value for each of the plurality of pixels; identifying specularities in the iris from the brightness values for each of the plurality of pixels, the specularities defining a brightest pixel set; determining a location corresponding to each pixel in the brightest pixel set; and identifying the iris in the at least one image from the location of each pixel in the brightest pixel set and a pattern formed by the brightest pixel set.