A Unified Approach Towards Multimedia Watermarking

The tremendous advancement of digital technology has increased the ease with which digital multimedia signals (image, video, audio) are stored, transmitted, and reproduced. Consequently, the content providers and owners are faced with problems of protection against copyright violation and other forms of abuse to their digital property. Digital watermarking has been proposed in the last decade as a solution to prevent illegal and malicious copying and distribution of digital media by embedding an unnoticeable information into the media content. This chapter describes three imperceptible and robust watermarking algorithms for different types of multimedia objects (image, video, audio). The three algorithms are based on cascading two powerful mathematical transforms; the Discrete Wavelet Transform (DWT), and the Singular Value Decomposition (SVD). The two transforms are different, and thus provide complementary levels of robustness against the same attack. In the proposed dual-transform algorithms, the watermark bits are not embedded directly on the wavelet coefficients, but rather on the elements of singular values of the DWT sub-bands of the multimedia object. Effectiveness of the proposed algorithms is demonstrated through extensive experimentation.