Improvement of On-line Signature Verification System Robust to Intersession Variability

In signature verification using on-line hand written data, we have shown that the pen inclination data improves the verification rate[1]. For the data of 9 weeks, we applied some reference renewal method to reduce the influence of intersession variability and obtained some improvement[2]. In this paper, we propose a threshold adaptation method, in which a reference renewal using the matching error of last five authenticated data is done. And, we show that the proposed method is effective to maintain verification rate with 91.2% using genuine and forgery signatures over 9 weeks.