Offline Chinese Signature Identification Based On 2-pass System

Signature is one of the most common biological features used for identity verification.Because of the significant advantages of signature identification as a way of personal identification such as:universality uniqueness stability and so on, it has a wide perspective applications in electronic-bank,military affairs, electronic-business,communication,office automation engineering files and so on. The research on this topic is not only important for practical applications but also the development of science.First,the application background,the development history and the researches at home and abroad of handwritten signature identification techniques are briefly introduced.The difficulties and main research methods of the off-line Chinese signature identification problem are analyzed.Then,the key techniques including image preprocessing,feature extraction and identification of off-line signature have been studied deeply in this thesis.The main researches include:The signatures,static shape feature and pseudo dynamic features have been extracted in feature extraction.The emphasis of shape feature is the pseudo-Zernike moment with rotation,scale and translation invariance and anti-noise character.The pseudo dynamic features high gray feature(HPF),framework aspect gray feature, and gray barycenter feature.In this thesis an off-line Chinese signature identification system based on pseudo feature and shape feature extraction is built furthermore,we adopted 2-pass identification method.As the writing styles are different,The signatures of different people vary from each other.The optional copy is easily identified using shape features.But it is difficult to find the intentional copies only using shape features. Imitating the writing press,peed and other dynamic features is difficult leads to superficially similar signatures have much difference.So we combine shape features with pseudo features to verify the using the feature fusion technique By this way we improve the ability of the signature identifications system. We try to improve the speed by using 2-pass verifying.The identification of 2-pass system is composed of two independent signature identification system.The first phase uses simple geometric features and pseudo-dynamic features to identify the authenticity of signatures,while the second phase uses Zernike moment to make a confirmation After the establishment of reference samples,when one pattern enters, the first phase of the inspection system to verify it.If it does not meet our requirements,we can judge it is false;if it have adopted the first phase,we use the second phase,Zernike moment to examine the characteristics.It has been proved that the identification of 2-pass system can save a lot of time for identification with out descending the correct identification rate.