48 research outputs found

    Spread spectrum-based video watermarking algorithms for copyright protection

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    Merged with duplicate record 10026.1/2263 on 14.03.2017 by CS (TIS)Digital technologies know an unprecedented expansion in the last years. The consumer can now benefit from hardware and software which was considered state-of-the-art several years ago. The advantages offered by the digital technologies are major but the same digital technology opens the door for unlimited piracy. Copying an analogue VCR tape was certainly possible and relatively easy, in spite of various forms of protection, but due to the analogue environment, the subsequent copies had an inherent loss in quality. This was a natural way of limiting the multiple copying of a video material. With digital technology, this barrier disappears, being possible to make as many copies as desired, without any loss in quality whatsoever. Digital watermarking is one of the best available tools for fighting this threat. The aim of the present work was to develop a digital watermarking system compliant with the recommendations drawn by the EBU, for video broadcast monitoring. Since the watermark can be inserted in either spatial domain or transform domain, this aspect was investigated and led to the conclusion that wavelet transform is one of the best solutions available. Since watermarking is not an easy task, especially considering the robustness under various attacks several techniques were employed in order to increase the capacity/robustness of the system: spread-spectrum and modulation techniques to cast the watermark, powerful error correction to protect the mark, human visual models to insert a robust mark and to ensure its invisibility. The combination of these methods led to a major improvement, but yet the system wasn't robust to several important geometrical attacks. In order to achieve this last milestone, the system uses two distinct watermarks: a spatial domain reference watermark and the main watermark embedded in the wavelet domain. By using this reference watermark and techniques specific to image registration, the system is able to determine the parameters of the attack and revert it. Once the attack was reverted, the main watermark is recovered. The final result is a high capacity, blind DWr-based video watermarking system, robust to a wide range of attacks.BBC Research & Developmen

    Evaluation of Multimedia Fingerprinting Image

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    Contribution to the construction of fingerprinting and watermarking schemes to protect mobile agents and multimedia content

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    The main characteristic of fingerprinting codes is the need of high error-correction capacity due to the fact that they are designed to avoid collusion attacks which will damage many symbols from the codewords. Moreover, the use of fingerprinting schemes depends on the watermarking system that is used to embed the codeword into the content and how it honors the marking assumption. In this sense, even though fingerprinting codes were mainly used to protect multimedia content, using them on software protection systems seems an option to be considered. This thesis, studies how to use codes which have iterative-decoding algorithms, mainly turbo-codes, to solve the fingerprinting problem. Initially, it studies the effectiveness of current approaches based on concatenating tradicioanal fingerprinting schemes with convolutional codes and turbo-codes. It is shown that these kind of constructions ends up generating a high number of false positives. Even though this thesis contains some proposals to improve these schemes, the direct use of turbo-codes without using any concatenation with a fingerprinting code as inner code has also been considered. It is shown that the performance of turbo-codes using the appropiate constituent codes is a valid alternative for environments with hundreds of users and 2 or 3 traitors. As constituent codes, we have chosen low-rate convolutional codes with maximum free distance. As for how to use fingerprinting codes with watermarking schemes, we have studied the option of using watermarking systems based on informed coding and informed embedding. It has been discovered that, due to different encodings available for the same symbol, its applicability to embed fingerprints is very limited. On this sense, some modifications to these systems have been proposed in order to properly adapt them to fingerprinting applications. Moreover the behavior and impact over a video produced as a collusion of 2 users by the YouTube鈥檚 s ervice has been s tudied. We have also studied the optimal parameters for viable tracking of users who have used YouTube and conspired to redistribute copies generated by a collusion attack. Finally, we have studied how to implement fingerprinting schemes and software watermarking to fix the problem of malicious hosts on mobile agents platforms. In this regard, four different alternatives have been proposed to protect the agent depending on whether you want only detect the attack or avoid it in real time. Two of these proposals are focused on the protection of intrusion detection systems based on mobile agents. Moreover, each of these solutions has several implications in terms of infrastructure and complexity.Els codis fingerprinting es caracteritzen per proveir una alta capacitat correctora ja que han de fer front a atacs de confabulaci贸 que malmetran una part important dels s铆mbols de la paraula codi. D'atra banda, la utilitzaci贸 de codis de fingerprinting en entorns reals est脿 subjecta a que l'esquema de watermarking que gestiona la incrustaci贸 sigui respectuosa amb la marking assumption. De la mateixa manera, tot i que el fingerprinting neix de la protecci贸 de contingut multim猫dia, utilitzar-lo en la protecci贸 de software comen莽a a ser una aplicaci贸 a avaluar. En aquesta tesi s'ha estudiat com aplicar codis amb des codificaci贸 iterativa, concretament turbo-codis, al problema del rastreig de tra茂dors en el context del fingerprinting digital. Inicialment s'ha q眉estionat l'efic脿cia dels enfocaments actuals en la utilitzaci贸 de codis convolucionals i turbo-codis que plantegen concatenacions amb esquemes habituals de fingerprinting. S'ha demostrat que aquest tipus de concatenacions portaven, de forma impl铆cita, a una elevada probabilitat d'inculpar un usuari innocent. Tot i que s'han proposat algunes millores sobre aquests esquemes , finalment s'ha plantejat l'煤s de turbocodis directament, evitant aix铆 la concatenaci贸 amb altres esquemes de fingerprinting. S'ha demostrat que, si s'utilitzen els codis constituents apropiats, el rendiment del turbo-descodificador 茅s suficient per a ser una alternativa aplicable en entorns amb varis centenars d'usuaris i 2 o 3 confabuladors . Com a codis constituents s'ha optat pels codis convolucionals de baix r脿tio amb dist脿ncia lliure m脿xima. Pel que fa a com utilitzar els codis de fingerprinting amb esquemes de watermarking, s'ha estudiat l'opci贸 d'utilitzar sistemes de watermarking basats en la codificaci贸 i la incrustaci贸 informada. S'ha comprovat que, degut a la m煤ltiple codificaci贸 del mateix s铆mbol, la seva aplicabilitat per incrustar fingerprints 茅s molt limitada. En aquest sentit s'ha plantejat algunes modificacions d'aquests sistemes per tal d'adaptar-los correctament a aplicacions de fingerprinting. D'altra banda s'ha avaluat el comportament i l'impacte que el servei de YouTube produeix sobre un v铆deo amb un fingerprint incrustat. A m茅s , s'ha estudiat els par脿metres 貌ptims per a fer viable el rastreig d'usuaris que han confabulat i han utilitzat YouTube per a redistribuir la copia fru茂t de la seva confabulaci贸. Finalment, s'ha estudiat com aplicar els esquemes de fingerprinting i watermarking de software per solucionar el problema de l'amfitri贸 malici贸s en agents m貌bils . En aquest sentit s'han proposat quatre alternatives diferents per a protegir l'agent en funci贸 de si 茅s vol nom茅s detectar l'atac o evitar-lo en temps real. Dues d'aquestes propostes es centren en la protecci贸 de sistemes de detecci贸 d'intrusions basats en agents m貌bils. Cadascuna de les solucions t茅 diverses implicacions a nivell d'infrastructura i de complexitat.Postprint (published version

    Anti-Collusion Fingerprinting for Multimedia

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    Digital fingerprinting is a technique for identifyingusers who might try to use multimedia content for unintendedpurposes, such as redistribution. These fingerprints are typicallyembedded into the content using watermarking techniques that aredesigned to be robust to a variety of attacks. A cost-effectiveattack against such digital fingerprints is collusion, whereseveral differently marked copies of the same content are combinedto disrupt the underlying fingerprints. In this paper, weinvestigate the problem of designing fingerprints that canwithstand collusion and allow for the identification of colluders.We begin by introducing the collusion problem for additiveembedding. We then study the effect that averaging collusion hasupon orthogonal modulation. We introduce an efficient detectionalgorithm for identifying the fingerprints associated with Kcolluders that requires O(K log(n/K)) correlations for agroup of n users. We next develop a fingerprinting scheme basedupon code modulation that does not require as many basis signalsas orthogonal modulation. We propose a new class of codes, calledanti-collusion codes (ACC), which have the property that thecomposition of any subset of K or fewer codevectors is unique.Using this property, we can therefore identify groups of K orfewer colluders. We present a construction of binary-valued ACCunder the logical AND operation that uses the theory ofcombinatorial designs and is suitable for both the on-off keyingand antipodal form of binary code modulation. In order toaccommodate n users, our code construction requires onlyO(sqrt{n}) orthogonal signals for a given number of colluders.We introduce four different detection strategies that can be usedwith our ACC for identifying a suspect set of colluders. Wedemonstrate the performance of our ACC for fingerprintingmultimedia and identifying colluders through experiments usingGaussian signals and real images.This paper has been submitted to IEEE Transactions on Signal Processing</I

    Error probabilities in Tardos codes

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    Anti-collusion forensics of multimedia fingerprinting using orthogonal modulation

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    Robust Logo Watermarking

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    Digital image watermarking is used to protect the copyright of digital images. In this thesis, a novel blind logo image watermarking technique for RGB images is proposed. The proposed technique exploits the error correction capabilities of the Human Visual System (HVS). It embeds two different watermarks in the wavelet/multiwavelet domains. The two watermarks are embedded in different sub-bands, are orthogonal, and serve different purposes. One is a high capacity multi-bit watermark used to embed the logo, and the other is a 1-bit watermark which is used for the detection and reversal of geometrical attacks. The two watermarks are both embedded using a spread spectrum approach, based on a pseudo-random noise (PN) sequence and a unique secret key. Robustness against geometric attacks such as Rotation, Scaling, and Translation (RST) is achieved by embedding the 1-bit watermark in the Wavelet Transform Modulus Maxima (WTMM) coefficients of the wavelet transform. Unlike normal wavelet coefficients, WTMM coefficients are shift invariant, and this important property is used to facilitate the detection and reversal of RST attacks. The experimental results show that the proposed watermarking technique has better distortion parameter detection capabilities, and compares favourably against existing techniques in terms of robustness against geometrical attacks such as rotation, scaling, and translation

    Digital video watermarking techniques for secure multimedia creation and delivery.

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

    Resilient Digital Image Watermarking for Document Authentication

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    Abstract鈥擶e consider the applications of the Discrete Cosine Transform (DCT) and then a Chirp coding method for producing a highly robust system for watermarking images using a block partitioning approach subject to a self-alignment strategy and bit error correction. The applications for the algorithms presented and the system developed include the copyright protection of images and Digital Right Management for image libraries, for example. However, the principal focus of the research reported in this paper is on the use of printscan and e-display-scan image authentication for use in e-tickets where QR code, for example, are embedded in a full colour image of the ticket holder. This requires that an embedding procedure is developed that is highly robust to blur, noise, geometric distortions such as rotation, shift and barrel and the partial removal of image segments, all of which are considered in regard to the resilience of the method proposed and its practical realisation in a real operating environment
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