Hiding Data in Halftone Images

Article type: Research Article

Authors: Tseng, Hsien-Wen | Chang, Chin-Chen

Affiliations: Library of National Taichung Teachers College, Taichung, Taiwan 403, R.O.C., e-mail: wen@mail.ntctc.edu.tw | Department of Computer Science and Information Engineering, National Chung Cheng University, Chaiyi, Taiwan 621, R.O.C., e-mail: ccc@cs.ccu.edu.tw

Abstract: Most recent papers about visual cryptography for halftone images are dedicated to get a higher contrast decoded image. However, the hidden visual pattern often blends into the background image and leads to a confused image. In this paper, we propose an improved method for halftone image hiding. By using the proposed method, the background image can be eliminated and the hidden visual pattern can be revealed precisely. Experimental results show that the decoded visual patterns could reveal good visual quality under various kinds of input patterns. Furthermore, better visual quality can be obtained when more halftone images are overlaid.

Keywords: data hiding, error diffusion, halftone, visual cryptography

Journal: Informatica, vol. 16, no. 3, pp. 419-430, 2005