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In the digital information network age, many media formats are easy to copy using a machine, allowing consumers to distribute copies via the Internet to their friends. On the other hand, digital media can be easily edited and modified by various multimedia tools. As a result, copy protection, digital rights management and content authentication have become three urgent and serious issues in the digital world. Copy protection refers to the technology attempting to frustrate copying, and not to make the legal remedies available to users whose copyrights are violated. Digital rights management (DRM) stands for the access control technology used by hardware manufacturers, publishers, copyright holders and individuals to inhibit uses of digital content that is not desired or intended by the content provider. Unlike data authentication techniques that check whether the data have been changed or not, content authentication refers to the technique used to verify whether the content or semantics of the media has been changed or not. Over the last two decades, digital watermarking has provided an effective solution to above problems. Digital watermarking describes the technologies to embed information, for example a number or a text or an image, into the digital media, such as images (Niu et al., 2000a, 2000b; Luo et al., 2011), video (Wang et al., 2005; Wang, Lu, Li, & Sun, 2009; Wang, Lu, Liang, & Zheng, 2009; Wu et al., 2011) and audio (Lu et al., 2005b; Yan et al., 2006), in order to protect the copyright or authenticate the content.