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Studies Of Digital Watermarking Of Information Security

Posted on:2004-03-21Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z M ZhangFull Text:PDF
GTID:1118360122961013Subject:Detection Technology and Automation
Abstract/Summary:PDF Full Text Request
With the rapid development of computer, network and communication, especially the popularization of the Internet, information security and copyright protection have been a key and attractive problem. A potential solution to alleviate this problem is to use invisible digital watermarking scheme, which refers to the embedding of secret messages, unobtrusive marks or labels that can be represented as bits into the digital multimedia.In this paper, we mainly describe the digital watermarking technologies of information security. We firstly introduced the research backgrounds, basic principles, application areas and recent development of the digital watermarking technology. Then we adopted some new technologies such as chaos, SVD (Singular Value Decomposition), ANNs (Artificial Neural Networks), ECC (Error Correction Code), into the digital watermarking and proposed several different kinds of watermarking schemes: watermarking with chaos control; watermarking in SVD domain; robustness enhancement with ANNs and ECC. The proposed schemes in this paper could cover the primary aspects of the image digital watermarking and fulfill the practical application's demands.This paper employed the characteristics of the HVS (Human Visual System) responded to the image contents and realized the two kinds of image-adaptive watermark algorithm, one is in the spatial domain based on the statistics theory and another in the DCT domain with meaningful digital watermark. The chaos sequence was applied in these two algorithms to increase its security and was served separately as the random watermark generator and the watermark image encryption techniques. Due to the analysis of the image characteristics, we determined the watermark strength by the classification of the image content and obtained better robustness and imperceptibility.New algorithms of meaningful digital watermarking in SVD domain with chaotic transform encryption are proposed. Based on the SVs characteristic analysis of image matrix, a visually recognizable binary image watermark is embedded into maximal singular value coefficient in block-based SVD transform domain of the cover image. Here we brought forward two primary schemes: one need original signal and the other is blind (without the originalcover). Experimental results show that our schemes can extract reliable copy of the hidden watermark from images that have been significantly degraded or altered through several common geometric distortions and signal processing operations.The most two important requirements of digital watermarking are the imperceptibility and robustness but it is hard to obtain a good balance between them. In this paper, we proposed two algorithms, which embed a visually recognizable binary image watermark into the host image, to enhance the robustness within the imperceptibility limit and degraded quality limit. The first one used an RBF neural network to mimic the HVS to achieve the adaptively different embedding maximum-strength according to the frequency component feature of the cover image. Experimental results show that the proposed techniques have good imperceptibility and can survive of common image processing operations and JPEG lossy compression with high robustness. The second one considered the watermarking system as a special digital communication system and introduced the ECC as channel coding technique. By using the Turbo coding technique, we are able to reduce the watermark bit error rate and improve the robustness of the watermark so as to make counterfeiting attacks more difficult.Finally, we make the summary of our works and introduce the achieved innovations in briefly. We also discussed the future works should be done of the digital watermarking.
Keywords/Search Tags:Digital Watermarking, Information Hiding, Chaos, Human Visual System, Copyright Protection, Artificial Neural Networks, Error Control Coding, Robustness Enhancement, Singular Value Decomposition
PDF Full Text Request
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