On-line Signature Verification Method by Laplacian Spectral Analysis and Dynamic Time Warping

As smartphones and touch screens are more and more popular, on-line signature verification technology can be used as one of personal identification means for mobile computing. In this paper, a novel Laplacian Spectral Analysis (LSA) based on-line signature verification method is presented and an integration framework of LSA and Dynamic Time Warping (DTW) based methods for practical application is proposed. In LSA based method, a Laplacian matrix is constructed by regarding the on-line signature as a graph. The signature's writing speed information is utilized in the Laplacian matrix of the graph. The eigenvalue spectrum of the Laplacian matrix is analyzed and used for signature verification. The framework to integrate LSA and DTW methods is further proposed. DTW is integrated at two stages. First, it is used to provide stroke matching results for the LSA method to construct the corresponding graph better. Second, the on-line signature verification results by DTW are fused with that of the LSA method. Experimental results on public signature database and practical signature data on mobile phones proved the effectiveness of the proposed method.