Identification of printing process using HSV colour space

Abstract

Inkjet and laser printers, and photocopiers are being increasingly used in criminal activities such as counterfeiting currency, creating forged documents, illegitimate business transactions and terrorism related acts. Identification of the printing process greatly aids in detecting such activities and is extensively used in the field of document examination. In this paper, we propose the use of image processing techniques in identifying the printing process used to generate a document. The characteristics of the various types of non-impact printing methods used by photocopiers, inkjet and laser printers are studied using colour image processing. HSV color space and, in particular, hue images at high-resolution, distribution of isolated spots in the vicinity of hue edge pixels and periodicities in edge intensity profiles distinguish between the different printing processes. Our initial study indicates their promise in replicating the results traditionally obtained by document examiners using a microscope or through chemical analysis. © Springer-Verlag Berlin Heidelberg 2006.