In this paper, we propose a new approach for symbolic representation of off-line signatures based on relative distances between centroids useful for verification. Distances between centroids of off-line signatures are used to form an interval valued symbolic feature vector for representing signatures. A method of off-line signature verification based on the symbolic representation is presented. We investigate the feasibility of the proposed representation scheme for signature verification on a MCYT_ signature database. We cluster similar signatures in each class and also investigate the cluster based symbolic representation for signature verification. Unlike other signature verification methods, the proposed method is simple and efficient. Several experiments are conducted to demonstrate the efficacy of the proposed scheme.

In this paper, we propose a new method of representing on-line signatures by interval valued symbolic features. Global features of on-line signatures are used to form an interval valued feature vectors. Methods for signature verification and recognition based on the symbolic representation are also proposed. We exploit the notions of writer dependent threshold and introduce the concept of feature dependent threshold to achieve a significant reduction in equal error rate. Several experiments are conducted to demonstrate the ability of the proposed scheme in discriminating the genuine signatures from the forgeries. We investigate the feasibility of the proposed representation scheme for signature verification and also signature recognition using all 16500 signatures from 330 individuals of the MCYT bimodal biometric database. Further, extensive experimentations are conducted to evaluate the performance of the proposed methods by projecting features onto Eigenspace and Fisherspace. Unlike other existing signature verification methods, the proposed method is simple and efficient. The results of the experimentations reveal that the proposed scheme outperforms several other existing verification methods including the state-of-the-art method for signature verification.