A two-step location approach combining coarse location with fine location is presented

and an extant iris location algorithm is improved in order to fasten the speed of iris location and make the iris location algorithm more robust. Grey scale projection approach is used for the coarse iris location and a kind of dynamic circular edge template is adopted by the fine iris location. Experiments show that the method has good performance of sub-pixel precision and about 1 second on speed compared with 3~5 seconds by the original iris location method. The two-step location approach can fasten location speed and decrease the blindness of search computation

and the improved iris location algorithm is reasonably more robust than the original one.