A Design of Iris Recognition System at a Distance
Iris recognition is a powerful biometrics for personal identification, but it is difficult to acquire good-quality iris images in real time. For making iris recognition more convenient to use, we design an iris recognition system at a distance about 3 meters. There are many key issues to design such a system, including iris image acquisition, human-machine-interface and image processing. In this paper, we respectively introduce how we deal with these problems and accomplish the engineering design. Experiments show that our system is convenient to use at the distance of 3 meters and the recognition rate is not worse than the state-of-the-art close-range systems. 1)Iris image acquisition: The human iris is very small and the required resolution for iris recognition is large, so it is diffi- cult to design the optical path for iris imaging at a distance. We carefully calculate the parameters of cameras, lens and illumi- nation intensity and elaborately select their types to set up the optical system. 2)Human-machine-interface: Because users are of differ- ent height, it is impossible for a single camera to cover so large range or for users to cooperate with the camera at a distance. We design a self-adaptive machine to automatically adapt to different people. Moreover, we use screens and audio signals to direct users to stand on the right position and give them mul- timedia feedback. All these devices are installed into a cabinet