ISSN : 1796-2048
Volume : 3    Issue : 4    Date : October 2008

Protecting Copyrights of Color Images using a Watermarking Scheme Based on Secret Sharing
and Wavelet Transform
Shang-Lin Hsieh, I-Ju Tsai, Bin-Yuan Huang, and Jh-Jie Jian
Page(s): 42-49
Full Text:
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This paper presents a novel digital watermarking scheme for copyright protection against piracy of
color images. Unlike traditional watermarking schemes that directly embed watermarks into host
images, the scheme encodes the watermark prior to watermark embedding to improve tolerance to
attacks. The process utilizes the secret sharing scheme with the feature extracted form the host
image by the discrete wavelet transform. Moreover, different from other watermarking schemes that
require manual adjustment in the embedding scaling factors to embed the watermark, the scheme
can automatically calculate the scaling factor for different images while still preserving robustness
and imperceptibility. The experimental results show that the scheme can resist several attacks
including cropping, scaling, and JPEG compression. Furthermore, the ability of extracting unique
features from different images, which is an important requirement for feature extraction, is also
demonstrated in the experiment.

Index Terms
copyright protection, digital watermarking, digital fingerprinting, secret sharing