Biometric and Forensic Aspects of Digital Document Processing

Signatures and handwriting have long played a role in dayto-day business transactions and in forensics, e.g., to authenticate documents, as evidence to establish crime or innocence, etc. The individuality of handwriting and signatures is the basis for their relevance to authentication and forensics. This very individuality makes them also potentially useful as a biometric modality. This chapter is concerned with automatic methods for verifying the writership of handwritten documents and signatures. The discussion consists of the individuality of handwriting, image pre-processing and interactive tools for forensic document examination, discriminating characteristics of handwriting, a statistical model of writer verification, and application of the model to signature verification.