Fingerprint image matching method syncretizing multi-reference node integral justification and direction field

Abstract

The invention discloses a fingerprint image matching method which integrates a plurality of reference nodes which are integrally aligned and direction fields. The method comprises the following steps: 1) extracting the information of local relative directions of the relative nodes surrounding a node; 2) carrying out rotation and translational rough aligning on the node set M(T) and M(Q) of a template fingerprint T and an input fingerprint Q; 3) building a process which leads (Rn#-(i)<Q>, Phi n#-(i)<Q>, Psi n#-(i)<Q>> i is equal to or more than 1, and is equal to or less than C) and (Rm n#-(i)<T>, Phi n#-(i)<T>, Psi m#-(i)<T>> i is equal to or more than 1, and is equal to or less than C) to be integrally aligned; 4) converting Mr#-(1)(T) and Mr#-(2)P<Q> into orthogonal coordinates and working out the finally matched node pairs Np of T and Q; 5) calculating the matched fraction STQ of T and Q; 6)giving out the direction fields O(T) and O(Q) of the fingerprint images T and Q to the fingerprint images which contain less nodes or do not contain nodes; 7) aligning the O(T) and O(Q) to obtain O<#>(Q) and calculating the matching degree c of O(T) and O<#>(Q); 8) applying a BP neuronic network to carry out similarity calculation. The fingerprint image matching method is suitable for the fingerprint images which do not contain nodes or are not abundant in nodes and has the advantages of quicker matching speed and higher identifying accuracy rate.

Description

technical field [0001] The invention relates to a matching method in fingerprint image recognition. Background technique [0002] Fingerprint matching is a key issue in fingerprint image recognition technology. Whether the fingerprint matching is accurate or not is directly related to the correctness of the final fingerprint image recognition. The current fingerprint identification system mainly adopts the matching method based on nodes, and a group of nodes is often used to represent a fingerprint. [0003] There are many methods for fingerprint matching. Experts have proposed many fingerprint matching algorithms, including methods based on syntax matching, methods based on image matching, methods based on optical correlation, methods based on WFMT features of grayscale images, and methods based on texture features. The method, the method of fingerprint matching based on the direction and frequency of local area extracted by GBF, the matching method of combining point mode...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the disadvantages of the existing fingerprint matching methods that the position and direction of the farther nodes become larger, the fingerprint image is not rich in nodes or does not contain nodes, and the matching speed is slow, the present invention provides a method suitable for A fingerprint image matching method that integrates the overall alignment of multiple reference nodes and the orientation field for a fingerprint image that does not contain nodes or is not rich in nodes, makes the position difference and direction difference of each matching node pair uniform, and the matching speed is faster

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