Abstract
Certain optical aberrations, such as defocus, can significantly degrade the signal collected by an imaging system, producing images with low resolution. In images with depth‐dependent detail, such degradations are difficult to remove due to their inherent spatially varying nature. In 1995, Dowski and Cathey introduced the concept of wavefront coding to extend the depth of field. They showed that wavefront coding and decoding enables quality control of such images using integrated optical‐digital imaging systems. With wavefront coding, a high‐resolution image can be efficiently obtained without the need to resort to expensive algorithms for spatially varying restoration. In this article, we discuss a novel and effective multiple‐design‐parameter approach for optimizing the processes of encoding and decoding the wavefront phase in integrated optical‐digital imaging systems. Our approach involves the use of information metrics, such as the Strehl ratio and Fisher information, for determining the optimal pupil‐phase distribution for which the resulting image is insensitive to certain aberrations, such as focus errors. The effectiveness of this approach is illustrated with a number of numerical simulation experiments, and applications to the development of iris recognition systems with high‐resolution capabilities are briefly discussed. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 67–74, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20009