An approach to computer-aided document examination

In this paper we describe a knowledge-based expert system capable of investigating a typewritten document and acquiring evidence on its falsification. A document is assumed to be falsified if its typing has been performed in multiple typing sessions. Verification of document authenticity is carried out by subjecting a document to four tests: alignment analysis, symbol comparison, gray level intensity analysis and type font identification. Tests are performed in succession and failure of any one of the tests signifies possible document falsificaton.