SigNet: Convolutional Siamese Network for Writer Independent Offline Signature Verification

TL;DR

SigNet employs a convolutional Siamese network to effectively distinguish genuine signatures from forgeries in writer-independent offline signature verification, demonstrating superior performance across multiple datasets and languages.

Contribution

This paper introduces SigNet, a novel convolutional Siamese network architecture specifically designed for writer-independent offline signature verification, outperforming existing methods on benchmark datasets.

Findings

SigNet achieves state-of-the-art accuracy on multiple signature datasets.

The network generalizes well across different languages and handwriting styles.

Experimental results confirm the effectiveness of Siamese networks in signature verification.

Abstract

Offline signature verification is one of the most challenging tasks in biometrics and document forensics. Unlike other verification problems, it needs to model minute but critical details between genuine and forged signatures, because a skilled falsification might often resembles the real signature with small deformation. This verification task is even harder in writer independent scenarios which is undeniably fiscal for realistic cases. In this paper, we model an offline writer independent signature verification task with a convolutional Siamese network. Siamese networks are twin networks with shared weights, which can be trained to learn a feature space where similar observations are placed in proximity. This is achieved by exposing the network to a pair of similar and dissimilar observations and minimizing the Euclidean distance between similar pairs while simultaneously maximizing it between dissimilar pairs. Experiments conducted on cross-domain datasets emphasize the capability of our network to model forgery in different languages (scripts) and handwriting styles. Moreover, our designed Siamese network, named SigNet, exceeds the state-of-the-art results on most of the benchmark signature datasets, which paves the way for further research in this direction.