title: Test of the Practicality and Feasibility of EDoF-Empowered Image Sensors for Long-Range Biometrics.
abstract: For many practical applications of image sensors, how to extend the depth-of-field (DoF) is an important research topic; if successfully implemented, it could be beneficial in various applications, from photography to biometrics. In this work, we want to examine the feasibility and practicability of a well-known "extended DoF" (EDoF) technique, or "wavefront coding," by building real-time long-range iris recognition and performing large-scale iris recognition. The key to the success of long-range iris recognition includes long DoF and image quality invariance toward various object distance, which is strict and harsh enough to test the practicality and feasibility of EDoF-empowered image sensors. Besides image sensor modification, we also explored the possibility of varying enrollment/testing pairs. With 512 iris images from 32 Asian people as the database, 400-mm focal length and F/6.3 optics over 3 m working distance, our results prove that a sophisticated coding design scheme plus homogeneous enrollment/testing setups can effectively overcome the blurring caused by phase modulation and omit Wiener-based restoration. In our experiments, which are based on 3328 iris images in total, the EDoF factor can achieve a result 3.71 times better than the original system without a loss of recognition accuracy.
authors.affiliation: Department of Photonics, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan. jack10313.eo00g@nctu.edu.tw.
authors.forename: Sheng-Hsun
authors.initials: SH
authors.lastname: Hsieh
authors.affiliation: Department of Computer Science & Information Engineering, National Central University, No. 300 Zhongda Road, Zhongli District, Taoyuan 32001, Taiwan. yunghui@csie.ncu.edu.tw.
authors.forename: Yung-Hui
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Photonics, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan. chtien@mail.nctu.edu.tw.
authors.forename: Chung-Hao
authors.initials: CH
authors.lastname: Tien
mesh_terms: D000465:Algorithms; D044466:Asian People; D001699:Biometry / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007498:Iris / Q000502:physiology; D010781:Photography / Q000379:methods
keywords: biometrics; extended depth of field; iris recognition; wavefront coding