An off-line signature verification system using an extracted displacement function

This paper proposes an off-line signature verification system based on a displacement extraction method. The optimum displacement functions are extracted for any pair of signatures using minimization of a functional. The functional is defined as the sum of the squared Euclidean distance between two signatures and a penalty term requiring smoothness of the displacement function. A coarse-to-fine search method is applied to prevent the calculation from stopping at local minima. Based on the obtained displacement function, the dissimilarity between a questionable signature and the corresponding authentic one is measured. The proposed system achieved error rate of 24.9% in a experiment. (C) 2002 Elsevier Science B.V. All rights reserved.