Master of Science / Department of Electrical and Computer Engineering / D. V. Satish Chandra / The area of health care delivery and medical data management has undergone a huge transformation in the recent years. This is directly related to the significant advancements in information and communication technologies. Vast amounts of medical data is to be efficiently stored, retrieved and distributed. The above mentioned reasons collectively have created new challenges, especially regarding the security of this highly sensitive information. Digital watermarking is a recently established area of research with many applications. The potential of medical image watermarking has only recently been realized by the research community. Medical image watermarking can be exploited to simultaneously address the issues of data security, archiving, retrieval and most importantly data authentication. This report discusses the perspectives of digital watermarking in the area of medical data management. Integer wavelet transform has been used to achieve reversible watermarking as every detail is important, especially in the case of medical images. Multiple watermarks which convey patient’s personal and examination data, keywords for information retrieval and the physician’s digital signature for authentication are embedded in an imperceptible manner. Different types of medical images have been acquired and tested using the proposed method.

University of Macau / Faculty of Science and Technology. / Department of Computer and Information Science

Chan Pik-Wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 111-130). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Research Objective --- p.3 / Chapter 1.3 --- Contributions --- p.4 / Chapter 1.4 --- The Structure of this Thesis --- p.6 / Chapter 2 --- Literature Review --- p.7 / Chapter 2.1 --- Security in Multimedia Communications --- p.8 / Chapter 2.2 --- Cryptography --- p.11 / Chapter 2.3 --- Digital Watermarking --- p.14 / Chapter 2.4 --- Essential Ingredients for Video Watermarking --- p.16 / Chapter 2.4.1 --- Fidelity --- p.16 / Chapter 2.4.2 --- Robustness --- p.17 / Chapter 2.4.3 --- Use of Keys --- p.19 / Chapter 2.4.4 --- Blind Detection --- p.20 / Chapter 2.4.5 --- Capacity and Speed --- p.20 / Chapter 2.4.6 --- Statistical Imperceptibility --- p.21 / Chapter 2.4.7 --- Low Error Probability --- p.21 / Chapter 2.4.8 --- Real-time Detector Complexity --- p.21 / Chapter 2.5 --- Review on Video Watermarking Techniques --- p.22 / Chapter 2.5.1 --- Video Watermarking --- p.25 / Chapter 2.5.2 --- Spatial Domain Watermarks --- p.26 / Chapter 2.5.3 --- Frequency Domain Watermarks --- p.30 / Chapter 2.5.4 --- Watermarks Based on MPEG Coding Struc- tures --- p.35 / Chapter 2.6 --- Comparison between Different Watermarking Schemes --- p.38 / Chapter 3 --- Novel Watermarking Schemes --- p.42 / Chapter 3.1 --- A Scene-based Video Watermarking Scheme --- p.42 / Chapter 3.1.1 --- Watermark Preprocess --- p.44 / Chapter 3.1.2 --- Video Preprocess --- p.46 / Chapter 3.1.3 --- Watermark Embedding --- p.48 / Chapter 3.1.4 --- Watermark Detection --- p.50 / Chapter 3.2 --- Theoretical Analysis --- p.52 / Chapter 3.2.1 --- Performance --- p.52 / Chapter 3.2.2 --- Capacity --- p.56 / Chapter 3.3 --- A Hybrid Watermarking Scheme --- p.60 / Chapter 3.3.1 --- Visual-audio Hybrid Watermarking --- p.61 / Chapter 3.3.2 --- Hybrid Approach with Different Water- marking Schemes --- p.69 / Chapter 3.4 --- A Genetic Algorithm-based Video Watermarking Scheme --- p.73 / Chapter 3.4.1 --- Watermarking Scheme --- p.75 / Chapter 3.4.2 --- Problem Modelling --- p.76 / Chapter 3.4.3 --- Chromosome Encoding --- p.79 / Chapter 3.4.4 --- Genetic Operators --- p.80 / Chapter 4 --- Experimental Results --- p.85 / Chapter 4.1 --- Test on Robustness --- p.85 / Chapter 4.1.1 --- Experiment with Frame Dropping --- p.87 / Chapter 4.1.2 --- Experiment with Frame Averaging and Sta- tistical Analysis --- p.89 / Chapter 4.1.3 --- Experiment with Lossy Compression --- p.90 / Chapter 4.1.4 --- Test of Robustness with StirMark 4.0 --- p.92 / Chapter 4.1.5 --- Overall Comparison --- p.98 / Chapter 4.2 --- Test on Fidelity --- p.100 / Chapter 4.2.1 --- Parameter(s) Setting --- p.101 / Chapter 4.2.2 --- Evaluate with PSNR --- p.101 / Chapter 4.2.3 --- Evaluate with MAD --- p.102 / Chapter 4.3 --- Other Features of the Scheme --- p.105 / Chapter 4.4 --- Conclusion --- p.106 / Chapter 5 --- Conclusion --- p.108 / Bibliography --- p.110

A digital watermark is a message robustly hidden within another digitized signal such as an image, a piece of music, a video, etc. . The principal applications of this technology are copyright protection and document fingerprinting. The robustness of watermarking algorithms against common geometrical deformations has drawn the attention of many researchers in the last ten years. Such distortions can result from usual processing of the media and/or malicious manipulations. As an example, a major concern for digital cinema industry is the illicit copy of movies with video cameras taking place in movie theaters. In this scenario, severe geometric distortions can jeopardize the retrieval of the watermark message from the illicit copies. The limitations and weaknesses of the previously proposed solutions to fight these distortions are presented. We developed a generalized construction method for periodic pseudo-random patterns. Based on these patterns, we designed a spread spectrum watermarking scheme with enhanced security properties. We investigated the detection probability and the interaction between exhaustive search and informed coding strategies. Finally, a scheme for the detection of a periodic structure and for the inversion of affine distortions was presented. We showed that the choice of the periodic repetition size involves a trade-off between robustness and secrecy. Thereafter, we studied the security flaw caused by the lack of secrecy in pilot-registration approaches. We proposed an innovative hiding scheme to remedy this issue. Our solution involves the extraction of robust local references from the content of the cover signal. Using this content normalized interpretation, we showed how one can design robust secret binary mask and modulate pilot signals in watermarking schemes. The efficiency of the approach is demonstrated on pilots derived from periodic structures. We also addressed the assessment of the degradation introduced by a geometrical distortion. We assume that a global rigid transform does not impair the perceptual value of an image and we propose a new criterion based on a local analysis of the geometrical deformations.

Digital watermarking is one of the most popular technologies for protecting the ownerships of digital contents or products. By embedding digital watermarks into digital contents, the owners of the contents can convince the judge or the trusted third party of their ownership of the contents. However, some attacks, such as the binding attacks and the men-in-the-middle attacks, are threatening the security of the watermarking mechanisms. Moreover, that the privacy of content buyers is not fully protected or the dispute between the buyers and the sellers cannot be fairly resolved also reduce the quality of the services. Although several buyer-seller watermarking protocols have been introduced in the literature, none can cope with all of the above problems. In this thesis, we will propose a novel buyer-seller watermarking protocol that can resolve the dispute between the buyers and the sellers fairly. Furthermore, not only is the proposed protocol immune to all of the known attacks, but it is truly buyer anonymous as well.

In recent years, there are more and more researches on semi-fragile watermarking scheme which can resist JPEG compression. But, there are few researches focused on the recovery of semi-fragile watermarked image. Therefore, in this paper, we not only present a semi-fragile watermarking scheme which can resist JPEG compression but use the error correction code (Reed-Solomon Code) to recover the area being malicious manipulated. At first, we use the semi-fragile watermarking scheme proposed by Lin and Hsieh to detect the counterfeit under the JPEG compression [9]. Its main effect is to resist JPEG compression and to detect the attacked parts without the need of the original image. And then, we will introduce how we use RS code to recover the attacked parts being detected by the semi-fragile watermarking scheme. We use the scheme ¡§Interleaving¡¨ to spread the local pixels to the global area. Next, we encode to each little image block by RS code. The redundant symbols generated by RS code will be signed to be signature attached with the watermarked image. Finally, the receiver can use semi-fragile watermarking scheme to detect attacked part and use the information of the signature to decode these attacked parts. Additionally, we also discuss how to decrease the load of the signature, thus, it can not significant loading of the watermarked image.

In this thesis, a number of novel watermarking techniques for different 3D representations are presented. A novel watermarking method is proposed for the mono-view video, which might be interpreted as the basic implicit representation of 3D scenes. The proposed method solves the common flickering problem in the existing video watermarking schemes by means of adjusting the watermark strength with respect to temporal contrast thresholds of human visual system (HVS), which define the maximum invisible distortions in the temporal direction. The experimental results indicate that the proposed method gives better results in both objective and subjective measures, compared to some recognized methods in the literature. The watermarking techniques for the geometry and image based representations of 3D scenes, denoted as 3D watermarking, are examined and classified into three groups, as 3D-3D, 3D-2D and 2D-2D watermarking, in which the pair of symbols identifies whether the watermark is embedded-detected in a 3D model or a 2D projection of it. A detailed literature survey on 3D-3D watermarking is presented that mainly focuses on protection of the intellectual property rights of the 3D geometrical representations. This analysis points out the specific problems in 3D-3D geometry watermarking , such as the lack of a unique 3D scene representation, standardization for the coding schemes and benchmarking tools on 3D geometry watermarking. For 2D-2D watermarking category, the copyright problem for the emerging free-view televisions (FTV) is introduced. The proposed watermarking method for this original problem embeds watermarks into each view of the multi-view video by utilizing the spatial sensitivity of HVS. The hidden signal in a selected virtual view is detected by computing the normalized correlation between the selected view and a generated pattern, namely rendered watermark, which is obtained by applying the same rendering operations which has occurred on the selected view to the original watermark. An algorithm for the estimation of the virtual camera position and rotation is also developed based on the projective planar relations between image planes. The simulation results show the applicability of the method to the FTV systems. Finally, the thesis also presents a novel 3D-2D watermarking method, in which a watermark is embedded into 3-D representation of the object and detected from a 2-D projection (image) of the same model. A novel solution based on projective invariants is proposed which modifies the cross ratio of the five coplanar points on the 3D model according to the watermark bit and extracts the embedded bit from the 2D projections of the model by computing the cross-ratio. After presenting the applicability of the algorithm via simulations, the future directions for this novel problem for 3D watermarking are addressed.

Thesis (M.S. in Applied Math and M.S. in Systems Engineering)--Naval Postgraduate School, March 2003. / Thesis advisor(s): Roberto Cristi, Ron Pieper, Craig Rasmussen. Includes bibliographical references (p. 119-121). Also available online.

Prior to the general availability of high speed Internet, the spread of piratedsoftware required the transfer of a physical copy like a disk, which limited therate at which illegal software could be distributed. The low transfer raterestricted software piracy to levels which producers found acceptable becausethe associated losses could be absorbed. Large scale cases of piracy were rareand when they did occur the legal system provided suitable retribution. However,recent advances in computer technology have made the need for a physical copyobsolete. Piracy is now a widespread, decentralized problem in which millions ofindividuals take part. Without technical means of identifying pirated software,the protection afforded by the legal system is no longer easy to enforce or costeffective.The research in this dissertation addresses the threat of software piracythrough the exploration of two techniques: software watermarking and softwarebirthmarking. Neither of these techniques can be used to prevent software theftentirely. Instead, they are used to detect occurrences of theft after the fact.One of the limiting factors of the protection provided by the legal system isthat it cannot be used to identify an incidence of piracy. Softwarewatermarking and birthmarking fill this gap, thus providing complimentaryprotection to the established legal protection. In this research, we analyze thestate of the art in both software watermarking and birthmarking and we propose anovel scheme in each of the areas which make significant improvements overexisting techniques.

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xiv, 195 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 181-195).