This paper describes a method to distinguish documents produced by laser printers, inkjet printers, and electrostatic copiers, three commonly used document creation devices. The proposed approach can distinguish between documents produced by these sources based on features extracted from the characters in the documents. Hence, it can also be used to detect tampered documents produced by a mixtu...

In this paper, the emissions of a laser printer, which may process classified information, are investigated in the media of electromagnetic radiation (ER), Power Line Conductors (PLC), and Signal Line Conductors (SLC). First, the candidate frequency points of Compromising Emanations (CE) are examined in the frequency domain. Second, the emitted signal is AM-demodulated with the proper bandwidth...

The market for colour printers based on electrophotographic systems is growing steadily. The sector exceeded 690,000 units in 2001 and is forecast to reach some 1.5 million units by 2005. The printer expected to be the main driving force behind this market expansion is the tandem type colour printer. The tandem colour printer has separate processes and recording systems for cyan, magenta, yello...

IBM PC/XT/AT and compatibles users of the popular graphics program Sigma-plot by Jandel Scientific (reviewed in Yale J Biol Med 61:174-175, 1988), who have recently acquired an HP Laserjet printer, may be surprised and disappointed. This program, which has performed so well for so many users of dot matrix printers and plotters, is abysmally slow when using a laser printer (output times in exces...

Printer identification based on printed documents can provide forensic information to protect copyright and verify authenticity. In addition to intrinsic features (intrinsic signatures) of the printer, modulating the printing process to embed specific signature (extrinsic signatures) will further extend the encoding capacity. In this paper we describe the use of laser modulation in electrophoto...

In our previous work, we have demonstrated techniques to embed and extract extrinsic signatures from halftone images and text documents. Well developed embedding algorithms should increase the payload capacity while enhance the reliability of detection. In this study, we will develop a printer model that will be used to optimize the embedding algorithm for capacity and detection reliability. Th...