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Journal of Information Science and Engineering, Vol. 22 No. 3, pp. 483-496 (May 2006)

Copyright Protection against Print-and-Scan Operations by Watermarking for Color Images Using Coding and Synchronizatin of Peak Locations in Frequency Domain*

Yen-Chung Chiu1 and Wen-Hsiang Tsai1,2
 1Department of Computer Science
National Chiao Tung University
Hsinchu, 300 Taiwan
2Department of Computer Science and Information Engineering
Asia Universiy
Taichung, 413 Taiwan

A watermarking method for copyright protection of color images against print-andscan operations is proposed. A watermark is embedded in an input image as coefficient- value peaks that are circularly and symmetrically distributed in a middle band of the discrete Fourier transform (DFT) domain of the input image. By detecting the robust peaks in the DFT domain of a reproduced image obtained by scanning a printed version of a watermarked image, we can extract the embedded watermark to verify the copyright of the reproduced image. Experimental results are given to prove the feasibility of the proposed method.

Keywords: digital watermarking, color image, copyright protection, print-and-scan operations, discrete Fourier transform, reproduced image

Full Text (¥þ¤åÀÉ) Retrieve PDF document (200605_01.pdf)

Received January 1, 2005; accepted August 16, 2005.
Communicated by C. C. Chiang, H. Y. Liao, and K. C. Fan.
* This work was supported in part by the NSC Project Advanced Technologies and Applications for Next Generation Information Networks (II) under Project No. NSC 93-2752-E-009-006-PAE and partially under NSC
Project No. NSC 94-2422-H-468-001.