Key Techniques and Methods for Imaging Iris in Focus

Automated iris recognition is a promising method for noninvasive verification of identity. How to acquire an iris image in focus is a key issue in iris recognition. Based on imaging properties of a simple lens, working principles of fixed focus and auto focus imaging systems are described. Key techniques for imaging iris in focus are discussed in this paper, such as illumination, lens design and self alignment to position the iris in the system´s depth of field. According to the techniques, a clear iris acquisition system is developed and experimental results are presented in this paper