Iris external boundary positioning method based on shades of gray and classifier

Abstract

An iris external boundary positioning method based on shades of gray and a classifier belongs to the technical field of image processing and relates to iris-identification technology. The method includes the following steps of: firstly determining an approximate region of the iris external boundary by pupil boundary information; secondly conducting histogram extension on the region and calculating lash gray threshold; subsequently using the shape and distribution characteristics of the iris external boundary to design two boundary point classifiers and obtain a point set of the iris external boundary; then according to the obtained point set of the iris external boundary, adopting a least square method to fit iris external boundaries ready to be selected; and finally utilizing pupil position information to compare the iris external boundaries ready to be selected and obtain the proximate iris external boundary curve. Compared with the existing iris external boundary positioning method, the iris external boundary positioning method has not only fast speed and accurate positioning, but also high robustness and the capability of still properly positioning an iris image with poor image quality, thus being conducive to improving the identification efficiency and accuracy of iris.

Description

technical field [0001] The invention belongs to the technical field of image processing, and mainly relates to iris identification technology in biometric identification. Background technique [0002] With the increasing demand for security protection, iris recognition, as a reliable, safe and usable biometric technology, has been gradually applied in various occasions with high security requirements. It has played a role that cannot be ignored in all aspects of social life such as e-commerce, national security, and entry-exit management. At the same time, iris recognition has begun to be applied in some developed countries of the world economy and technology. For example, in banks, public security, airports, networks, etc., iris recognition has been successfully applied. For example, the iris identification system developed by Siemens Nixdorf and integrated in ATMs, the iris scanning identification system trialed at New York's Kennedy Airport and Boston's Logan Airport, a...

AI Technical Summary

Problems solved by technology

However, this method is more dependent on the quality of the iris image. Once the interference is obvious and the noise increases, the outer edge of the iris cannot be correctly located.

However, when some advanced algorithms such as morphology or SNAKE method are used, the real-time requirements of the system are difficult to break through.

In addition, the current methods for locating the outer boundary of the iris do not locate the iris image with poor image quality, especially for some noise types with obvious eyelash occlusion, the current methods cannot accurately and quickly locate the iris image.

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