Accurate personal identification is becoming more and more important to the operation of our ever increasingly electronically inter-connected information soci- ety. Traditional personal identification technologies cannot satisfy the increasing security requirements. Due to its uniqueness and stability, biometrics has become the most promising way to meet such requirements. Being the oldest and the most mature biometrics, fingerprint is the most widely used personal identifica- tion method. In this thesis, we study the fingerprint image matching algorithms. The main contributions of this thesis include the following issues: ① The orientation field, which is a stable global features of fingerprint images, is employed in fingerprint matching, making matching algorithms integrate global features with local ones. ② An IC card oriented fingerprint matching algorithm is presented. Taking full consideration of the limitations of processing speed and storage space of IC card systems, this algorithm makes use of orientation field of fingerprint images as a new feature in the registration and computation of matching scores. Combining local features (minutiae) with global ones (orientation field), this algorithm tries to solve the problem that fingerprints cannot be discriminated solely using minutiae when relatively few minutiae available, making it possible to increase matching accuracy at the cost of little increase of storage and computation cost. ③ A mutual information based fingerprint matching algorithm is presented. This algorithm finds the accurate alignment by maximization of mutual in- formation between features extracted from orientation field of template and input fingerprint images. Then matching result is jointly given by minu- tiae matching and maximal mutual information achieved in registration. To speed up registration, we takes a hierarchical method. The prominent char- acteristics of this algorithm is that it much resembles human behavior of comparing fingerprints, which results in reduced occurrences of misalign- ment and improved registration accuracy. In this thesis, we first give an introduction to the fundamental definitions, system architecture and evaluations of automatic fingerprint identification sys- tems (AFIS). Then, a comprehensive survey is presented on the state of the art of fingerprint image matching algorithms.Afterwards,we detailed our IC card oriented fingerprint matching algorithm and mutual information based fingerprint matching algorithm.Finally,a summary of our work and a vista of future research are presented.
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