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Optical Engineering • Open Access

Computer-generated hologram watermarking resilient to rotation and scaling
Author(s): Min Liu; Guanglin Yang; Haiyan Xie; Mingyao Xia; Jianbin Hu; Hongbin Zha

Paper Abstract

We propose a new scheme of computer-generated hologram (CGH) watermarking to resist rotation and scaling. To embed the inverse log-polar mapping of a mark pattern's CGH into a cover image, the twin image of the mark pattern can be directly reconstructed by fast Fourier transformation from the log-polar mapping of the watermarked image after rotation and scaling, not requiring a registration step in the extracting procedure. In an experiment, the information position of the twin image is located in the high-frequency domain and the redundant information of the low-frequency component is properly eliminated, so the contrast of the twin image is appropriately enhanced and the basic information of the mark pattern is effectively preserved to be recognized. The experimental results show that the mark-pattern's information can be effectively reconstructed when the watermarked image is scaled by 0.5 to 2 or rotated by any angle, so this watermarking scheme is effectively verified by experiment.

Paper Details

Date Published: 1 June 2007
PDF: 3 pages
Opt. Eng. 46(6) 060501 doi: 10.1117/1.2744330
Published in: Optical Engineering Volume 46, Issue 6
Show Author Affiliations
Min Liu, Peking Univ. (China)
Guanglin Yang, Peking Univ. (China)
Haiyan Xie, Peking Univ. (China)
Mingyao Xia, Peking Univ. (China)
Jianbin Hu, Peking Univ. (China)
Hongbin Zha, Peking Univ. (China)

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