A constructive and unifying framework for zero-bit watermarking

In the watermark detection scenario, also known as zero-bit watermarking, a watermark, carrying no hidden message, is inserted in content. The watermark detector checks for the presence of this particular weak signal in content. The article looks at this problem from a classical detection theory point of view, but with side information enabled at the embedding side. This means that the watermark signal is a function of the host content. Our study is twofold. The first step is to design the best embedding function for a given detection function, and the best detection function for a given embedding function. This yields two conditions, which are mixed into one `fundamental' partial differential equation. It appears that many famous watermarking schemes are indeed solution to this `fundamental' equation. This study thus gives birth to a constructive framework unifying solutions, so far perceived as very different.Comment: submitted to IEEE Trans. on Information Forensics and Securit

Digital steganalysis: Computational intelligence approach

In this paper, we present a consolidated view of digital media steganalysis from the perspective of computational intelligence.In our analysis the digital media steganalysis is divided into three domains which are image steganalysis, audio steganalysis, and video steganalysis.Three major computational intelligence methods have also been identified in the steganalysis domains which are bayesian, neural network, and genetic algorithm.Each of these methods has its own pros and cons

Tatouage vidéo utilisant l'ACI et basé sur un treillis informé

L'Analyse en Composantes Indépendantes (ACI) a été utilisée récemment dans plusieurs schémas de tatouage. Il s'avère important d'évaluer la robustesse d'un système de tatouage dans cet espace et de la comparer par rapport à celles réalisées dans d'autres espaces, notamment celui obtenu par la Transformée en Cosinus Discrète (TCD). Ainsi, nous proposons dans cet article d'évaluer la performance d'un schéma de tatouage informé, utilisant l'ACI, et de montrer ses principaux intérêts et inconvénients par rapport à d'autres domaines. Pour ce faire, nous présentons une méthode de tatouage basée sur le treillis modifié d'un code convolutif, et opérant dans deux espaces transformés à l'aide d'une TCD ou d'une ACI. Le système ainsi proposé assure, dans les deux domaines, un niveau de robustesse important, ainsi qu'une capacité d'insertion intéressante pour les applications d'augmentation de contenu. Dans cet article, nous nous intéressons à l'application suivante : le tatouage constitue un canal caché transmis au sein d'un canal de TV numérique, compressé par MPEG-2

Robust digital image watermarking algorithms for copyright protection

Digital watermarking has been proposed as a solution to the problem of resolving copyright ownership of multimedia data (image, audio, video). The work presented in this thesis is concerned with the design of robust digital image watermarking algorithms for copyright protection. Firstly, an overview of the watermarking system, applications of watermarks as well as the survey of current watermarking algorithms and attacks, are given. Further, the implementation of feature point detectors in the field of watermarking is introduced. A new class of scale invariant feature point detectors is investigated and it is showed that they have excellent performances required for watermarking. The robustness of the watermark on geometrical distortions is very important issue in watermarking. In order to detect the parameters of undergone affine transformation, we propose an image registration technique which is based on use of the scale invariant feature point detector. Another proposed technique for watermark synchronization is also based on use of scale invariant feature point detector. This technique does not use the original image to determine the parameters of affine transformation which include rotation and scaling. It is experimentally confirmed that this technique gives excellent results under tested geometrical distortions. In the thesis, two different watermarking algorithms are proposed in the wavelet domain. The first algorithm belongs to the class of additive watermarking algorithms which requires the presence of original image for watermark detection. Using this algorithm the influence of different error correction codes on the watermark robustness is investigated. The second algorithm does not require the original image for watermark detection. The robustness of this algorithm is tested on various filtering and compression attacks. This algorithm is successfully combined with the aforementioned synchronization technique in order to achieve the robustness on geometrical attacks. The last watermarking algorithm presented in the thesis is developed in complex wavelet domain. The complex wavelet transform is described and its advantages over the conventional discrete wavelet transform are highlighted. The robustness of the proposed algorithm was tested on different class of attacks. Finally, in the thesis the conclusion is given and the main future research directions are suggested

Tatouage informé basé sur un treillis : application à la vidéo

né - Le tatouage informé est basé sur la construction d'un dictionnaire de codage partitionné en des sous-dictionnaires correspondants aux différents messages à insérer. Dans ce cadre, l'utilisation des codes correcteurs d'erreurs permet d'effectuer une recherche efficace dans le dictionnaire et d'assurer une distance importante entre les mots de code du dictionnaire. Miller et al. [11] ont proposé un système de tatouage informé basé sur la modification du treillis d'un code convolutif. Après une introduction des principales méthodes proposées en tatouage informé, nous utilisons le système de Miller et al. dans le cadre de tatouage des séquences vidéos : nous étendons le tatouage sur plusieurs images. Ce qui permet d'améliorer les performances de la méthode en terme de qualité du document tatoué. Le système ainsi proposé assure un niveau de robustesse important face à des attaques de traitement de signal, ainsi qu'une capacité d'insertion intéressante pour les applications d'augmentation de contenu