Digital Watermarking and Data Hiding in Multimedia

 

Abstract

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In the past decade the= re has been an explosion in the use and distribution of digital multimedia data. Electronic commerce applications and on-line services are rapidly being developed. Although digital data has many advantages over analog data, serv= ice providers are reluctant to offer services in digital format because they fe= ar unrestricted duplication and publication of copyrighted material.

Data embedding in multi= media could help in providing proof of origin and distribution of content. This communication could control access, provide customized delivery, and provide solutions for pay-per-view implementations. This work is concerned with the development and use of digital watermarking technology to embed signature d= ata within multimedia content. This is done by exploring the application of channel coding techniques known fo= r digital communication to effectively improve the performance of the data embedding system.

In this application we = have developed several new techniques for robust data embedding into images and video data. These techniques enable embedding large amounts of data and facilitate signature recovery in the absence of the original host. The channel codes u= sed in this research comprises of block codes such as BCH and Reed-Solomon, the other codes used were the convolutional codes, trellis codes, and concatena= ted codes. Several interesting applications of these embedding methods to lossless text data recovery from lossy compressed imag= es, and images in images and images in video hiding, are presented.

Maximum likelihood deco= ding using Viterbi algorithm is employed in extracti= ng the hidden information. Results were compared to the uncoded messages and the improvement in the performance is quite noticeable. The algorithms were also tested against JPEG compression and noise attacks. The signature data was recognizable even after high compression ratios and large noise addition.

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