Abstract Broadband communication networks and multimedia data available in a digital format opened many challenges and opportunities for innovation. Versatile and simple-to-use software and decreasing prices of digital devices have made it possible for consumers from all around the world to create and exchange multimedia data. Broadband Internet connections and near error-free transmission of data facilitate people to distribute large multimedia files and make identical digital copies of them. A perfect reproduction in digital domain have promoted the protection of intellectual ownership and the prevention of unauthorized tampering of multimedia data to become an important technological and research issue. Digital watermarking has been proposed as a new, alternative method to enforce intellectual property rights and protect digital media from tampering. Digital watermarking is defined as imperceptible, robust and secure communication of data related to the host signal, which includes embedding into and extraction from the host signal. The main challenge in digital audio watermarking and steganography is that if the perceptual transparency parameter is fixed, the design of a watermark system cannot obtain high robustness and a high watermark data rate at the same time. In this thesis, we address three research problems on audio watermarking: First, what is the highest watermark bit rate obtainable, under the perceptual transparency constraint, and how to approach the limit? Second, how can the detection performance of a watermarking system be improved using algorithms based on communications models for that system? Third, how can overall robustness to attacks to a watermark system be increased using attack characterization at the embedding side? An approach that combined theoretical consideration and experimental validation, including digital signal processing, psychoacoustic modeling and communications theory, is used in developing algorithms for audio watermarking and steganography. The main results of this study are the development of novel audio watermarking algorithms, with the state-of-the-art performance and an acceptable increase in computational complexity. The algorithms' performance is validated in the presence of the standard watermarking attacks. The main technical solutions include algorithms for embedding high data rate watermarks into the host audio signal, using channel models derived from communications theory for watermark transmission and the detection and modeling of attacks using attack characterization procedure. The thesis also includes a thorough review of the state-of-the-art literature in the digital audio watermarking.

For digital media, the risk of piracy is aggravated by the ease to copy and distribute the content. Watermarking has become the technology of choice for discouraging people from creating illegal copies of digital content. Watermarking is the practice of imperceptibly altering the media content by embedding a message, which can be used to identify the owner of that content. A watermark message can also be a set of instructions for the display equipment, providing information about the content’s usage restrictions. Several applications are considered and three watermarking solutions are provided. First, applications such as owner identification, proof of ownership, and digital fingerprinting are considered and a fast content-dependent image watermarking method is proposed. The scheme offers a high degree of robustness against distortions, mainly additive noise, scaling, low-pass filtering, and lossy compression. This method also requires a small amount of computations. The method generates a set of evenly distributed codewords that are constructed via an iterative algorithm. Every message bit is represented by one of these codewords and is then embedded in one of the image’s 8 × 8 pixel blocks. The information in that particular block is used in the embedding so as to ensure robustness and image fidelity. Two watermarking schemes designed to prevent theatre camcorder piracy are also presented. In these methods, the video is watermarked so that its display is not permitted if a compliant video player detects the watermark. A watermark that is robust to geometric distortions (rotation, scaling, cropping) and lossy compression is required in order to block access to media content that has been recorded with a camera inside a movie theatre. The proposed algorithms take advantage of the properties of the dual-tree complex wavelet transform (DT CWT). This transform offers the advantages of both the regular and the complex wavelets (perfect reconstruction, approximate shift invariance and good directional selectivity). Our methods use these characteristics to create watermarks that are robust to geometric distortions and lossy compression. The proposed schemes are simple to implement and outperform comparable methods when tested against geometric distortions. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Digital watermarking of multimedia content has been proposed as a method for different applications such as copyright protection, content authentication, transaction tracking and data hiding. In this thesis, we propose a lossless watermarking approach based on Discrete Cosine Transform (DCT) for a new application of watermarking. A depth map obtained from a stereoscopic image pair is embedded into one of the two images using a reversible watermarking algorithm. Different from existing approaches which hide depth map in spatial domain, the depth information is hidden in the quantized DCT domain of the stereo image in our method. This modification makes the watermarking algorithm compatible with JPEG and MPEG-2 compression. After the investigation of the quantized DCT coefficients distribution of the compressed image and video, The bit-shift operation is utilized to embed the depth map into its associated 2D image reversibly for the purpose of achieving high compression efficiency of the watermarked image and/or video and high visual quality of stereo image and/or video after the depth map is extracted. We implement the proposed method to analyze its performance. The experimental results show that a very high payload of watermark (e.g. depth map) can be embedded into the JPEG compressed image and MPEG-2 video. The compression efficiency is only slightly reduced after the watermark embedding and the quality of the original image or video can be restored completely at the decoder side.

Les modèles 3D sont des contenus précieux très utilisés dans l'industrie, et donc la cible potentielle de piratages. Le tatouage robuste pour les maillages 3D apporte une réponse au problème du traçage de traître. Dans l'état de l'art du domaine, la couche d'adaptation du contenu en particulier est testée face des attaques standards. Une approche robuste à la pose est alors étudiée. Elle utilise une estimation robuste de l'épaisseur, définie comme la distance un nuage de points construits à partir de mesures du diamètre. Les performances expérimentales montrent qu'elle forme un point de départ prometteur pour le tatouage robuste de maillages 3D posés. Pour les maillages statiques, la modulation des distances radiales est une approche efficace du tatouage. Elle a été formulée comme un problème d'optimisation quadratique sous contrainte, dont nous proposons plusieurs extensions : une transformée par étalement, des primitives de référence calculées de manière intégrale, des directions de déplacement arbitraires, et de nouvelles métriques pour minimiser la distorsion perçue par un utilisateur. Des expériences illustrent leurs bénéfices pour le compromis entre la robustesse et la fidélité du tatouage. La sécurité est analysée par l'intermédiaire de deux mécanismes de protection et par une série d'attaques et de contre-Mesures. Un système de resynchronisation est intégré afin d'améliorer la résistance au rognage. Des points de recalage sont insérés dans une configuration spécifique qui porte les informations habituellement éliminées par l'attaque. Au décodage, elles sont récupérées de manière aveugle. Un gain significatif des performances est mesuré expérimentalement. / 3D models are valuable assets widely used in the industry and likely to face piracy issues. This dissertation deals with robust mesh watermarking that is used for traitor-Tracing. Following a review of state-Of-The-Art 3D watermarking systems, the robustness of several content adaptation transforms are benchmarked. An embedding domain robust against pose is investigated, with a thickness estimation based on a robust distance function to a point cloud constructed from some mesh diameters. A benchmark showcases the performance of this domain that provides a basis for robust watermarking in 3D animations. For static meshes, modulating the radial distances is an efficient approach to watermarking. It has been formulated as a quadratic programming problem minimizing the geometric distortion while embedding the payload in the radial distances. This formulation is leveraged to create a robust watermarking framework, with the integration of the spread-Transform, integral reference primitives, arbitrarily selected relocation directions and alternate metrics to minimize the distortion perceived. Benchmarking results showcase the benefits of these add-Ons w.r.t the fidelity vs. robustness watermarking trade-Off. The watermark security is then investigated with two obfuscation mechanisms and a series of attacks that highlight the remaining limitations. A resynchronization approach is finally integrated to deal with cropping attacks. The resynchronization embeds land-Marks in a configuration that conveys synchronization information that will be lost after cropping. During the decoding, this information is blindly retrieved and significant robustness improvements are achieved.

This work shares purpose with new directions in the philosophy of intellectual property, where self-expression and participation in the creation of culture are seen as key ingredients of human wellbeingand autonomy. A technical solution is explored that enables major labels and independent creatorsto publish music with equal reach to audiences, without the need for trusted third parties.The principal contribution is a buyer-seller protocol in the setting of untrusted service providersand a blockchain ledger. In the envisioned scenario, files are streamed from untrusted providers toend users. Encryption and watermarking, rather than obfuscation, are used to protect against anddisincentivize piracy. Watermarking bit rate, storage and communication overheads, and encryptionperformance are key parameters. Subscription and ad-supported pricing models are discussed. / Detta arbete delar syfte med nya idéer inom immaterialrättsfilosofi, där yttrande och delaktighet iskapandet av kultur ses som nödvändiga ingredienser för mänskligt välbefinnande och självständighet.Rapporten utforskar en teknisk lösning som möjliggör för stora mediebolag och oberoende artister attpublicera musik med samma åtkomst till publik, utan behov av betrodda tredjeparter.Det huvudsakliga bidraget är ett köpar-säljar-protokoll för en miljö med obetrodda service providersoch en blockchain ledger. I det föreställda sceneriot skickas filer från obetrodda parter till slutan-vändare. Kryptering och vattenmärkning, snarare än obfuskering, används för att skydda mot ochavskräcka från piratkopiering. Vattenmärkningens bithastighet, lagrings- och kommunikations-behov,samt krypteringens prestanda är avgörande parametrar. Subscription och ad-supported som prismod-eller diskuteras.

Media such as movies and images are nowadays produced and distributed digitally. It is usually simple to make copies of digital content. Consequently illegal pirate copies can be duplicated and distributed in large quantities. One way to deter authorized content receivers from illegally redistributing the media is watermarking. If individual watermarks are contained in the digital media and a receiver is a pirate and redistributes it, the pirate at the same time distributes his identity. Thus a located pirate copy can be traced back to the pirate. The watermarked media should otherwise be indistinguishable from the original media content. To distribute media content scalable transmission methods such as broadcast and multicast should be used. This way the distributor will only need to transmit the media once to reach all his authorized receivers. But since the same content is distributed to all receivers the requirement of individual watermarks seems to be contradictory. In this thesis we will show how individually watermarked media content can be transmitted in a scalable way. Known methods will be reviewed and a new method will be presented. The new method is independent of what type of distribution that is used. A system with robust watermarks that are difficult to remove is described. Only small parts of the media content will be needed to identify the pirates. The method will only give a small data expansion compared to distribution of non-watermarked media. We will also show how information theory tools can be used to expand the amount of data in the watermarks given a specific size of the media used for the watermarking. These tools can also be used to identify parts of the watermark that have been changed by deliberate deterioration of the watermarked media, made by pirates. / <p>Report code: LiU-Tek-Lic-2005:67.</p>

The FFT has been a staple in the field of mathematics and computer science for almost 60 years. And yet, it still endures as an efficient algorithm in a multitude of fields. However, as significant technical advances has been made since its inception the demand on methods constantly get higher and higher, and the FFT is seldom enough to solve the problems of this day and age on its own. So how does the FFT perform on its own with today’s standards? This thesis aims to use the FFT to create two algorithms, an Image Denoising algorithm and a Digital Watermarking algorithm respectively, and analyse the efficacy of the algorithms with today’s standards. The results showed that the FFT on its own competently tackles problems well, however with increased demands on the algorithms, the limitations of the FFT became apparent. This underscores the prevalent trend of integrating the FFT with other specializedmethods, ensuring its continued relevance in an era of continuously advancing technologicaldemands.

No / This paper examines and evaluates a new robust and fragile watermarking scheme for colour images captured by mobile phone cameras. The authentication has been checked by using the fragile watermarking, while the copyright protection has been examined by using the robust one. The mobile phone number, including the international code, is a unique number across the whole world and it is used as a robust watermark. The number is embedded in the frequency domain using the discrete wavelet transform. On the other hand, hash codes are used as fragile watermarks and inserted in the spatial domain of the RGB image. The scheme is blind and the extraction process of the watermarks (Robust and Fragile) does not require the original image. The fragile watermark can detect any tampering in the image while the robust watermark is strong enough to survive against several attacks. The watermarking algorithm causes minimal distortion to the images. The proposed algorithm has been successfully tested, evaluated and compared with other algorithms.

This thesis deals with the development and evaluation of blind discrete cosine transform-based watermarking algorithms for copyright protection of digital still images using handwritten signatures and mobile phone numbers. The new algorithms take into account the perceptual capacity of each low frequency coefficients inside the Discrete Cosine Transform (DCT) blocks before embedding the watermark information. They are suitable for grey-scale and colour images. Handwritten signatures are used instead of pseudo random numbers. The watermark is inserted in the green channel of the RGB colour images and the luminance channel of the YCrCb images. Mobile phone numbers are used as watermarks for images captured by mobile phone cameras. The information is embedded multiple-times and a shuffling scheme is applied to ensure that no spatial correlation exists between the original host image and the multiple watermark copies. Multiple embedding will increase the robustness of the watermark against attacks since each watermark will be individually reconstructed and verified before applying an averaging process. The averaging process has managed to reduce the amount of errors of the extracted information. The developed watermarking methods are shown to be robust against JPEG compression, removal attack, additive noise, cropping, scaling, small degrees of rotation, affine, contrast enhancements, low-pass, median filtering and Stirmark attacks. The algorithms have been examined using a library of approximately 40 colour images of size 512 512 with 24 bits per pixel and their grey-scale versions. Several evaluation techniques were used in the experiment with different watermarking strengths and different signature sizes. These include the peak signal to noise ratio, normalized correlation and structural similarity index measurements. The performance of the proposed algorithms has been compared to other algorithms and better invisibility qualities with stronger robustness have been achieved.

In the immediate future, multimedia product distribution through the Internet will become main stream. However, it can also have the side effect of unauthorized duplication and distribution of multimedia products. That effect could be a critical challenge to the legal ownership of copyright and intellectual property. Many schemes have been proposed to address these issues; one is digital watermarking which is appropriate for image and video copyright protection. Videos distributed via the Internet must be processed by compression for low bit rate, due to bandwidth limitations. The most widely adapted video compression standard is MPEG-4. Discrete cosine transform (DCT) domain watermarking is a secure algorithm which could survive video compression procedures and, most importantly, attacks attempting to remove the watermark, with a visibly degraded video quality result after the watermark attacks. For a commercial broadcasting video system, real-time response is always required. For this reason, an FPGA hardware implementation is studied in this work. This thesis deals with video compression, watermarking algorithms and their hardware implementation with FPGAs. A prototyping VLSI architecture will implement video compression and watermarking algorithms with the FPGA. The prototype is evaluated with video and watermarking quality metrics. Finally, it is seen that the video qualities of the watermarking at the uncompressed vs. the compressed domain are only 1dB of PSNR lower. However, the cost of compressed domain watermarking is the complexity of drift compensation for canceling the drifting effect.