Iris texture normalization method based on dual-spring model

Abstract

The invention relates to an iris texture normalization method based on a dual-spring model. The method includes that ration of pupil radius to iris radius is set under an iris standard state, and ratio of the width of a near-pupil to the width of (near-pupil area + far-pupil area) is set under an iris standard state; the number of required sampling lines of the near-pupil area and the far-pupil area is set; the near-pupil area and the far-pupil area are modeled into series connected springs with different elastic coefficients; lower-pupil radius, near-pupil area width and far-pupil area widthunder a standard state are calculated according to iris actual radius; inner circumference and outer circumference of an iris are divided equally, correspondingly and respectively, coordinates of a certain point on the edge of a pupil and coordinates of a point arranged on the edge of the iris and corresponding to the point on the edge of the pupil are calculated, and distance between the two points is calculated; when the iris is under the non-standard state, the width of the near-pupil area and the far-pupil area is calculated, and linear sampling is conducted on the near-pupil area and thefar-pupil area; and sampling points are normalized into a rectangular image. Compared with the existing non-linear normalization method, the method is simple and practical, can reduce errors caused by pupil contracting and expanding, and can increase recognition rate of iris recognition.

Description

technical field [0001] The invention relates to the technical field of eye iris recognition, in particular to an iris texture normalization method. Background technique [0002] With the development of network and information technology, personal identification has received unprecedented attention and is facing more and more severe tests. Biometrics is an emerging research discipline that uses various physiological and morphological characteristics inherent in the human body as the identification medium to uniquely identify individuals and conduct personal identity authentication. Compared with traditional identification methods, identification technology based on biometric identification has the advantages of not being easily forgotten or lost, good anti-counterfeiting performance, and portable. [0003] As an important biological feature, the iris has the advantages of natural protected characteristics, high complexity, high stability, and high anti-counterfeiting when us...

AI Technical Summary

Problems solved by technology

The above two nonlinear normalization methods are improved compared with the traditional linear normalization method, and both use relevant mathematical models to correct the nonlinear compression of the iris, but the above two calculation methods are relatively complicated and the amount of calculation Large, difficult to engineer, and the actual effect is not accurate enough

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