Abstract: To solve the problems that the iris localization is too long, the inner edge of iris is
not ideal circular, and eyelids or eyelashes commonly exist, a novel method of iris image
preprocessing is presented. The false edge points of iris are greatly reducing by mathematical
morphology operator to process the iris image. Finally, eyelashes and eyelids are detected by double
line fitting. Testing on the CASIA－IrisV3 database, experiment results show that the proposed
algorithm has a high performance on speed and precision, and eyelids and eyelashes detection
algorithm can remove eyelid and eyelashes reasonable and effectively.

Key words: image preprocessing, mathematical morphology, iris location, eyelid detection;
eyelash detection