Abstract—It is very common for paper documents to be copied and falsified. In view of the limitations of existing anti-copying methods, we propose a method to distinguish the photocopies and printouts based on average grayscale difference (AGD). By embedding the information layer pattern into background layer pattern, this method can distinguish the information layer pattern be recognizable in printouts, while unrecognizable in photocopies. Thus, the anti-copying effect can be achieved. In this paper, the impact of the AGD on anti-copying effect is analyzed theoretically and experimentally. Particularly, the impact of the radius and the gray value of the background circle on anti-copying performance is studied. The experimental results show the anti-copying performance of the proposed method. The method can distinguish the printouts and photocopies effectively and precisely with background circle radius R=8 and grayscale of 170.
Index Terms—Average gray difference, anti-copying, printouts, photocopies.
Lu Zhang, De Li, and Hua Jin are with Department of Computer Science, Yanbian University, Yanji, China (e-mail: 1214522050@qq.com, leader1223@ybu.edu.cn, hjin@ybu.edu.cn).
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Cite:Lu Zhang, De Li, and Hua Jin, "A Novel Anti-copying Method Based on Average Grayscale Difference," International Journal of Computer Theory and Engineering vol. 12, no. 1, pp. 15-21, 2020.
Copyright © 2020 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
