Digital watermarking algorithms based on wavelet transforms provide increased performance and perceptual quality. This thesis proposes two wavelet-based schemes: one robust and one fragile. Robust watermarks should withstand attacks, such as compression, while maintaining the data integrity. The first approach presented is an algorithm which implements image watermarking in the domain of an overcomplete, or redundant, wavelet transform. Alternately, fragile watermarks are intended for use in applications wherein any loss of image quality is not acceptable. In the second approach presented, data embedding in the domain of an integer wavelet transform is considered. An algorithm is proposed that uses a bilevel image coder to compress a chosen bitplane, thereby providing space in which to store a payload while guaranteeing perfect image recovery.

When video transmits over error-prone channels, the fragile property of compressed stream makes it sensitive to bit error. Often even a slight error can make video unable to correctly decode. Therefore, there is a need for a good error control method to solve the problem. This paper presents a novel error detection and concealment strategy along with watermark technique. The proposed watermark-based scheme utilizes two kinds of watermark technique, a fragile watermark is used to detect and localize errors, and a robust watermark is used to reconstruct error areas when errors exist. Experimental results show the proposed watermark-based scheme has good error detection capabilities and complete error recovery information, therefore significant improves video quality after errors happened, especially in the case of higher loss probabilities.

Digital image watermarking has gained a great interest in the last decade among researchers. Having such a great community which provide a continuously growing list of proposed algorithms, it is rapidly finding solutions to its problems. However, still we are far away from being successful. Therefore, more and more people are entering the field to make the watermarking idea useful and reliable for digital world. Of these various watermarking algorithms, some outperform others in terms of basic watermarking requirements like robustness, invisibility, processing cost, etc. In this thesis, we study the performances of different watermarking algorithms in terms of robustness. Algorithms are chosen to be representatives of different categories such as spatial and transform domain. We evaluate the performance of a selected set of 9 different methods from the watermarking literature against again a selected set of attacks and distortions and try to figure out the properties of the methods that make them vulnerable or invulnerable against these attacks.

Depuis plus de vingt ans, l'accès à la technologie est devenu très facile étant donné son omniprésence dans le quotidien de chacun et son faible coût. Cet accès aux technologies du numérique permet à toute personne équipée d'un ordinateur ou d'un smartphone de visualiser et de modifier des contenus digitaux. Avec les progrès en matière de stockage en ligne, la quantité de contenus digitaux tels que le son, l'image ou la vidéo sur internet a explosé et continue d'augmenter.Savoir identifier la source d'une image et certifier si celle-ci a été modifiée ou non sont des informations nécessaires pour authentifier une image et ainsi protéger la propriété intellectuelle et les droits d’auteur par exemple. Une des approches pour résoudre ces problèmes est le tatouage numérique. Il consiste à insérer une marque dans une image qui permettra de l'authentifier.Dans cette thèse, nous étudions premièrement le tatouage numérique dans le but de proposer des méthodes plus robustes aux modifications d'image grâce aux codes correcteurs. En étudiant la structure des erreurs produites par la modification d’une image marquée, un code correcteur sera plus efficace qu’un autre. Nous proposons aussi d’intégrer de nouveaux codes correcteurs appelés codes en métrique rang pour le tatouage.Ensuite, nous proposons d’améliorer l'invisibilité des méthodes de tatouage pour les images couleur. A l’insertion d’une marque, les dégradations de l’image sont perçues différemment par le système visuel humain en fonction de la couleur. Nous proposons un modèle biologique de la perception des couleurs qui nous permet de minimiser les distorsions psychovisuelles de l’image à l’insertion.Toutes ces techniques sont testées sur des images naturelles dans un contexte d’insertion d’information. / For more than twenty years, technology has become more and more easy to access. It is omnipresent in everyday life and is low cost. It allows anyone using a computer or a smartphone to visualize and modify digital contents. Also, with the impressive progress of online massive data storage (cloud), the quantity of digital contents has soared and continues to increase. To ensure the protection of intellectual property and copyright, knowing if an image has been modified or not is an important information in order to authenticate it. One approach to protect digital contents is digital watermarking. It consists in modifying an image to embed an invisible mark which can authenticate the image. In this doctorate thesis, we first study how to improve the robustness of digital image watermarking against image processings thanks to error correcting codes. By studying the error structure produced by the image processing applied on a watermarked image, we can find an optimal choice of error correcting code for the best correction performances. Also, we propose to integrate a new type of error correcting codes called rank metric codes for watermarking applications. Then, we propose to improve the invisibility of color image watermarking methods. At the embedding step, a host image suffers some distortions which are perceived differently in function of the color by the human visual system. We propose a biological model of color perception which allows one to minimize psychovisual distortions applied on the image to protect.