Improving semi-text-independent method of writer verification using difference vector

The semi-text-independent method of writer verification based on the linear framework is a method that can use all characters of two handwritings to discriminate the writers in the condition of knowing the text contents. The handwritings are allowed to just have small numbers of even totally different characters. This fills the vacancy of the classical text-dependent methods and the text-independent methods of writer verification. Moreover, the information, what every character is, is used for the semi-text-independent method in this paper. Two types of standard templates, generated from many writer-unknown handwritten samples and printed samples of each character, are introduced to represent the content information of each character. The difference vectors of the character samples are gotten by subtracting the standard templates from the original feature vectors and used to replace the original vectors in the process of writer verification. By removing a large amount of content information and remaining the style information, the verification accuracy of the semi-text-independent method is improved. On a handwriting database involving 30 writers, when the query handwriting and the reference handwriting are composed of 30 distinct characters respectively, the average equal error rate (EER) of writer verification reaches 9.96%. And when the handwritings contain 50 characters, the average EER falls to 6.34%, which is 23.9% lower than the EER of not using the difference vectors.

[1]  Y.Y. Tang,et al.  Chinese handwriting-based writer identification by texture analysis , 2004, Proceedings of 2004 International Conference on Machine Learning and Cybernetics (IEEE Cat. No.04EX826).

[2]  Keinosuke Fukunaga,et al.  Introduction to Statistical Pattern Recognition , 1972 .

[3]  Nei Kato,et al.  A Handwritten Character Recognition System Using Directional Element Feature and Asymmetric Mahalanobis Distance , 1999, IEEE Trans. Pattern Anal. Mach. Intell..

[4]  J. Friedman Regularized Discriminant Analysis , 1989 .

[5]  Xin Li,et al.  An Off-line Chinese Writer Retrieval System Based on Text-sensitive Writer Identification , 2006, 18th International Conference on Pattern Recognition (ICPR'06).

[6]  Eric O. Postma,et al.  Improving automatic writer identification , 2005, BNAIC.

[7]  Cheng-Lin Liu,et al.  Extracting individual features from moments for Chinese writer identification , 1995, Proceedings of 3rd International Conference on Document Analysis and Recognition.

[8]  Xiaoqing Ding,et al.  Writer identification using directional element features and linear transform , 2003, Seventh International Conference on Document Analysis and Recognition, 2003. Proceedings..

[9]  Horst Bunke,et al.  Off-line handwriting identification using HMM based recognizers , 2004, Proceedings of the 17th International Conference on Pattern Recognition, 2004. ICPR 2004..

[10]  Horst Bunke,et al.  Off-line writer identification using Gaussian mixture models , 2006 .

[11]  Xiaoqing Ding,et al.  An effective writer verification algorithm using negative samples , 2004, Ninth International Workshop on Frontiers in Handwriting Recognition.

[12]  Louis Vuurpijl,et al.  Writer identification using edge-based directional features , 2003, Seventh International Conference on Document Analysis and Recognition, 2003. Proceedings..

[13]  Tieniu Tan,et al.  Biometric personal identification based on handwriting , 2000, Proceedings 15th International Conference on Pattern Recognition. ICPR-2000.

[14]  Lambert Schomaker,et al.  Text-Independent Writer Identification and Verification Using Textural and Allographic Features , 2007, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[15]  Sung-Hyuk Cha,et al.  Individuality of handwriting. , 2002, Journal of forensic sciences.

[16]  Isao Yoshimura,et al.  Off-line writer verification using ordinary characters as the object , 1991, Pattern Recognit..

[17]  Tieniu Tan,et al.  Personal identification based on handwriting , 2000, Pattern Recognit..