In this paper, we introduce a new technology to extract the unique features from an iris image, which uses scale-space filtering. Resulting iris code can be used to develop a system for rapid and automatic identification of persons, with high reliability and confidence levels. First, an iris part is separated from the whole image. Then the radius and center of the iris are obtained. Once the regions that have a high possibility of being noise are discriminated, the features presented in the highly detailed pattern is then extracted from the iris image. Scale-space filtering technique is applied for feature extraction.