Gwenaël Doërr

ContentArmor SAS · R&D

If you hold a common banknote up to the light, a watermarked drawing appears. This watermark is invisible during normal use and carries some information about the object in which it is embedded. The watermarks of two different kind of banknotes are indeed different. This watermark is directly inserted into the paper during the papermaking process....

Camcorder piracy refers to the process of using a camcorder to record a screen that displays copyrighted content. In contrast to the previous works that aimed at detecting the occurrence of camcorder piracy, this paper conducts an in-depth study of the luminance flicker that is naturally present in camcorded videos due to the interplay between a li...

We describe a new watermarking system based on the principles of informed coding and informed embedding. This system is capable of embedding 1380 bits of information in images with dimensions 240×368 pixels. Experiments on 2000 images indicate the watermarks are robust to significant valumetric distortions, including additive noise, low-pass filter...

Today, comparing audio watermarking systems remain a challenge due to the lack of publicly-available reference algorithms. In addition, robustness against acoustic path transmission is only occasionally evaluated. This jeopardizes the chances of digital watermarking to be adopted in the context of applications where such a feature is vital, e.g., s...

Information forensics and security (IFS) is an active R&D area whose goal is to ensure that people use devices, data, and intellectual properties for authorized purposes and to facilitate the gathering of solid evidence to hold perpetrators accountable. For over a quarter century, since the 1990s, the IFS research area has grown tremendously to add...

Spatio-temporal desynchronization remains a major challenge for watermarking system as it could impair the detection of the hidden payload. Over the years, several (non-blind) registration techniques have been proposed to realign the analyzed content prior to watermark detection and thereby achieve robustness against severe attacks such as display-...

This book explains how to measure the security of a watermarking scheme, how to design secure schemes but also how to attack popular watermarking schemes. This book gathers the most recent achievements in the field of watermarking security by considering both parts of this cat and mouse game. This book is useful to industrial practitioners who woul...

Disparity coherent watermarking has been introduced as a means to address the unique characteristics of stereoscopic visual content. This strategy has been reported to notably improve robustness performances in prior works, especially with respect to virtual view synthesis. While disparity coherence has always been conjectured to also provide bette...

Correlation-based watermark detection inherently assumes that a pseudo-random watermark pattern is present in the cover signal at a given location. However, disparity-coherent watermarks for stereo video content are broken into pieces which are offset one with respect to the others. Acoustic transmission yields echoes due to multi-path propagation...

Cryptography-based content protection is an efficient means to protect multimedia content during transport. Nevertheless, content is eventually decrypted at rendering time, leaving it vulnerable to piracy e.g. using a camcorder to record movies displayed on an LCD screen. Such type of piracy naturally imprints a visible flicker signal in the pirate...

In the context of stereo video, disparity-coherent watermarking has been introduced to provide superior robustness against virtual view synthesis, as well as to improve perceived fidelity. Still, a number of practical considerations have been overlooked and in particular the role of the underlying depth estimation tool on performances. In this arti...

Camcording a screen is a common and easy way for a pirate to capture a protected video and circumvent any cryptography-based protection system like DRM. Therefore, antipiracy methods like watermarking should be robust to this type of attack. One effect very often encountered is the flicker effect: image luminance varies periodically along the video...

To be relevant in copyright protection scenarios, watermarking systems need to provide appropriate levels of security. This paper investigates the security of a popular 3D watermarking method that alters the histogram of distances between the vertices of a surface mesh and its center of mass using a quadratic programming formulation.We study two co...

A large portion of pirate movies illegally shared over the Internet is either a camcorded copy of a projection in a digital cinema or is directly ripped from optical discs such as DVDs and Blu-ray discs. In this paper, we introduce a classifier that automatically discriminates between these two types of piracy in an effort to provide tools that hel...

Modulating the distances between the vertices and the center of mass of a triangular mesh is a popular approach to watermark 3D objects. Prior work has formulated this approach as a quadratic programming problem which minimizes the geometric distortion while embedding the watermark payload in the histogram of distances. To enhance this framework ,...

Content owners are reluctant to deliver premium content to open devices due to the risk of piracy and the corresponding potential for loss of revenue. To lift this deadlock, there is increasing interest in incorporating watermarking-based tracing mechanisms onto mobile devices such as smart phones and tablets. The scarcity of resources calls for in...

Collaborative creation workflows are calling for softer protection mechanisms than conventional encryption. Geometry-preserving en-cryption relates to protection techniques for 3D objects that alter the visual representation of the object after rendering but preserves some geometrical primitives, e.g. the bounding box. The advantage of this approac...

A watermarking strategy for triangle surface meshes consists of modifying the vertex positions along the radial directions, in order to adjust the distribution of radial distances and thereby encode the desired payload. To guarantee that watermark embedding does not alter the center of mass, prior work formulated this task as a quadratic programmin...

Content protection relies on several security mechanisms: (i) encryption to prevent access to the content during transport, (ii) trusted computation environment to prevent access during decoding, and we can also add (iii) forensic watermarking to deter content re-acquisition at rendering. With the advent of next generation video and the ever increa...

HTTP adaptive streaming has become the dominant solution for broadband streaming delivery. Essentially, the server delivers small chunks of content in response to queries from a player, that can alternate between different qualities of content depending on its rendering capabilities and the network condition. In this paper, we highlight that the fr...

Stereo video content calls for new watermarking strategies, e.g. to achieve robustness against virtual view synthesis. Prior works focused either on inserting the watermark in an invariant domain or on guaranteeing that the watermarks introduced in the left and right views are coherent with the disparity of the scene. However, the first approach ra...

Nowadays, forensic watermarks are introduced at projection time in movie theater. This provides the Entertainment industry with a tracing mechanism to identify indelicate cinema owners, who would have let camcorders enter their premises. However, the watermarking technologies deployed in film-based theaters and digital cinemas differ. For cost effi...

This paper introduces a geometry-preserving protection paradigm that heavily distorts 3D objects while preserving some intrinsic geometrical property (e.g. the bounding box or the convex hull), thereby avoiding a global corruption of the whole 3D scene. Backward compatibility is guaranteed de facto : legacy non-compliant rendering engines can displ...

Video watermarking systems operating directly in the compressed bit stream are receiving increasing interest due to their ease of integration into existing content delivery workflows. Such algorithms, however, usually involve a strong dependency to the underlying video codec. In other words, the throughput of the system, e.g. the embedding rate, is...

The invention relates to a method for watermark embedding in multi views video comprising a plurality of views captured with a plurality of cameras comprising for each view a step of projecting the view onto a domain invariant to the plurality of views and to intermediate synthesized view, which depends on the locations, orientations, and intrinsic...

Despite the academic focus on blind detection, many forensic watermarking systems actually operate in a non-blind fashion to accommodate for real-life desynchronization attacks. In other words, the original content is needed to perform watermark detection e.g. to re-align the pirate sample with the original content prior to watermark decoding. A so...

A number of technologies claim to be robust against content re-acquisition with a camera recorder e.g. water- marking and content ngerprinting. However, the benchmarking campaigns required to evaluate the impact of the camcorder path are tedious and such evaluation is routinely overlooked in practice. Due to the interaction between numerous devices...

AC-3 audio compression find applications in home cinema, DVD, BD and digital television. This paper addresses the challenge of transparently watermarking AC-3 bit streams instead of the conventional decoding - baseband watermarking - re-encoding approach. We discuss the alternate possibilities to embed watermarks by altering the MDCT coefficients d...

We propose a new method to detect resampled imagery. The method is based on examining the normalized energy density present within windows of varying size in the second derivative of the image in the frequency domain, and exploiting this characteristic to derive a 19-D feature vector that is used to train a SVM classifier. Experimental results are...

This paper presents an approach to evaluate the acoustic path transmission of watermarked audio tracks through large scale simulations. The multitude of signal alterations performed implicitly via acoustic path transmission are aggregated through the measurement of impulse responses. These impulse responses are integrated in a test suite in order t...

Digital camcording in the premises of cinema theaters is the main source of pirate copies of newly released movies. To trace such recordings, watermarking systems are exploited in order for each projection to be unique and thus identifiable. The forensic analysis to recover these marks is different for digital and legacy cinemas. To avoid running b...

D video content has been receiving increasing interest over the last few months and created challenges regarding how to protect such high valued items. For instance, depth-image-based rendering techniques allowing for the creation of virtual views may impair underlying watermarks embedded within individual views. In contrast with previous works, th...

We propose a new method to detect re-sampled imagery. The method is based on examining the normalized energy density present within windows of varying size in the second derivative of the frequency domain, and exploiting this characteristic to derive a 19-dimensional feature vector that is used to train a SVM classifier. Experimental results are re...

Psychoacoustic models are routinely used in audio watermarking algorithms to adjust the changes induced by the watermarking process to the sensitivity of the ear. The performances of such models in audio watermarking applications are tightly related to the determination of tonal and noise-like components. In this paper, we present an improved tonal...

The weighted overlap add (WOLA) technique is routinely used in audio processing to avoid introducing audible clicks. This process introduces inter-dependencies between WOLA coefficients and it is thus necessary to revisit watermarking algorithms to accommodate for such dependencies and prevent introducing self-inflicted interferences. In this paper...

Psychoacoustic models are routinely used in audio watermarking algorithms to adjust the changes induced by the watermarking process to the sensitivity of the ear. The performances of such models in audio watermarking applications are tightly related to the determination of tonal and noise-like components. In this paper, we present an improved tonal...

Digital rights management (DRM) technologies have recently received many blows that might hamper their future. Copyright holders, by imposing tight restrictions on their assets' usability, have managed to infuriate consumers to the point at which the music industry has partly dropped DRM. Is multimedia content protection dead? Well, not quite yet....

In this industrial exhibit, Technicolor will showcase various technologies developed to protect digital audio-visual material all along the media value chain, from production to distribution, including forensics services in case pirated content is detected. The exhibit will be organized around Technicolor's proprietary technologies in video fingerp...

Prior works on re-quantization detection were mainly focused on still images and videos, implying that the involved quantization is uniform. In this paper, we examine non-uniform re-quantization, and then investigate the automatic detection of re-compressed speech signals. Based on Fisher Linear Discriminant (FLD), two detection algorithms are desc...

Re-quantization commonly occurs when digital multimedia content is being tampered with. Detecting requantization is therefore an important element for assessing the authenticity of digital multimedia content. In this paper, we introduce three features based on the observation that re-quantization (i) induces periodic artifacts and (ii) introduces d...

Motion coherency has recently been identified as a desirable property for watermarks embedded within video streams in order to withstand temporal frame averaging along the motion axis. Nevertheless, no tool has been proposed to easily evaluate the motion coherency of a given watermarking system. Today, this assessment relies on a computationally ex...

In this paper we argue that improved interoperability between DRM systems is likely to benefit to all the actors in the content value chain. Moreover, we describe a domain-based approach to DRM interoperability. We discuss in some detail configuration aspects of such interoperable domains, and how they affect certain social aspects such as marriage...

We compare the performance of three steganalysis system for detection of plus/minus 1 steganography. We examine the relative performance of each system on three commonly used image databases. Experimental results clearly demonstrate that both absolute and relative performance of all three algorithms vary considerably across databases. This sensitiv...

Recently Zhang et al described an algorithm for the detection of plusmn1 LSB steganography based on the statistics of the amplitudes of local extrema in the greylevel histogram. Experimental results demonstrated performance comparable or superior to other state-of-the-art algorithms. In this paper, we describe improvements to this algorithm to (i)...

Benchmarking watermarking systems now goes beyond only evaluating the ability of the embedded watermark to with- stand common signal primitives such as filtering, resampling, lossy compression, D/A-A/D conversions, etc. Evaluation procedures have to consider how much information leaks from a watermarking system since such knowledge could prove most...

Considerable progress has been made in the detection of steganographic algorithms based on replacement of the least significant bit (LSB) plane. However, if LSB matching, also known as -1 embedding, is used, the detection rates are considerably reduced. In particular, since LSB embedding is modeled as an additive noise process, detection is especia...

This paper analyses the security of dirty paper trellis (DPT) watermarking schemes which use both informed coding and informed em- bedding. After recalling the principles of message embedding with DPT watermarking, the secret parameters of the scheme are highlighted. The security weaknesses of DPT watermarking are then presented: in the wa- termark...

Lattice codes and quantization-based techniques have received considerable attention as a method of digital wa-termarking with side information. However, these algorithms are also recognized to be highly sensitive to common signal processing primitives such as valuemetric scaling, e.g. changes in volume of a song, or re-quantization, e.g. JPEG comp...

This book constitutes the thoroughly refereed post-proceedings of the 9th International Workshop on Information Hiding, IH 2007, held in Saint Malo, France, in June 2007. The 25 revised full papers presented were carefully reviewed and selected from 105 submissions. The papers are organized in topical sections on new steganographic schemes, waterma...

Digital watermarking has been introduced in the 1990s as a complementary technology for copyright protection. In an effort to anticipate hostile behavior of adversaries, the research community is constantly introducing new attacks to benchmark watermarking systems. In this paper, we present a generic attack strategy based on block replacement. As m...

The fields of cryptography and communications are quite distinct and while communications systems often combine technologies from the two fields, a layered architecture is applied that permits each layer to be independently designed. It is generally agreed that watermarking, i.e. the embedding and decoding of messages within content, is a form on c...

In previous work, we demonstrated how perceptual modeling can be applied to dither modulated quantization index modulation and rational dither modulation, to improve both robustness and fidelity. These algorithms were shown to be significantly more robust to valumetric scaling. However, they, and their predecessors, remain extremely sensitive to re...

Geometrical distortions are the Achilles heel for many watermarking schemes. Most countermeasures proposed in the literature only address the problem of global affine transforms (e.g., rotation, scaling, and translation). In this paper, we propose an original blind watermarking algorithm robust to local geometrical distortions such as the deformati...

Motion coherent watermarking has been recently proposed as a means to combat temporal frame averaging along the motion axis (MC-TFA). The fundamental idea consists in exploiting motion-compensation primitives to force a physcal point of the scene to always carry the same watermark sample wherever it is projected in the video. However, for a given w...

Dirty paper trellis codes have been introduced as an alternative to lattice codes to implement watermarking as communications with side information. Their key feature is robustness against value-metric scaling in comparison with lattice codes. Despite the strong academic recognition, parametrization issues remain unclear. For instance, the impact o...

Résumé L'évaluation de la sécurité des algorithmes de tatouage est récemment devenue une préoccupation majeure. Ainsi, les attaques par collusion se sont révélées une menace impor-tante lorsque des stratégies de tatouage image par image sont utilisées en vidéo. Typiquement, plusieurs trames vi-déo tatouées sont combinées pour obtenir des trames non...

Security issues have almost been ignored during the first decade of digital watermarking. As a result, many released watermarking algorithms are weak against hostile intelligence. For instance, block replacement attacks defeat watermarking systems which do not consider the self-similarities of the host signal during embedding. Such attacks replace...

Dirty paper trellis codes are a form of watermarking with side information. These codes have the advantage of being invariant to valuemetric scaling of the cover work. However, the original proposal requires a computational expensive second stage, informed embedding, to embed the chosen code into the cover Work. In this paper, we present a computat...

Multimedia digital data is highly redundant: successive video frames are very similar in a movie clip, most songs contain some repetitive patterns, etc. This property can consequently be exploited to successively replace each part of the signal with a similar one taken from another location in the same signal or with a combination of similar parts....

Block replacement attacks consist in exploiting the redundancy of the host signal to replace each signal block with another one or a combination of other ones. Such an attacking strategy has been recognized to be a major threat against watermarking systems e.g. additive spread-spectrum and quantization index modulation algorithms. In this paper, a...

Collusion approaches in general, and block replacement attacks in particular, have been demonstrated to be a major threat against the security of frame-by-frame embedding strategies in video water-marking. These attacks exploit the redundancy of the host signal to replace each signal block with another perceptually similar one taken from another lo...

Most of the watermarking algorithms can still be defeated by geometric distortions today. If the weakness against global distortions can almost be considered as solved, local geometric distortions such as the ones introduced by StirMark remain a major issue. In this paper, an original resynchronization method is presented as a potential countermea-...

Digital watermarking has first been introduced as a possible way to ensure intellectual property (IP) protection. However, fifteen years after its infancy, it is still viewed as a young technology and digital watermarking is far from being introduced in Digital Right Management (DRM) frameworks. A possible explanation is that the research community...

Watermarking digital video material is usually considered as watermarking a sequence of still images. However, such a frame-by-frame approach is very risky since straightforward embedding strategies can result in poor performance in terms of security i.e., against hostile attacks. As examples, two very common video-watermarking systems will be pres...

Unauthorized digital copying is a major concern for multi-media content providers. Since copyright owners lose control over content distribution as soon as data is decrypted or unscrambled, digital watermarking has been introduced as a complementary protection technology. In an effort to anticipate hostile behaviors of adversaries, the research com...

Digital watermarking was introduced during the last decade as a complementary technology to protect digital multimedia data. Watermarking digital video material has already been studied, but it is still usually regarded as watermarking a sequence of still images. However, it is well-known that such straightforward frame-by-frame approaches result i...

The security issue has been neglected for a long time in digital watermarking. Recent results for video watermarking have pointed out that existing watermarking schemes are not secure, i.e., a hostile intelligence succeeds in removing the hidden watermarks. In particular, for a given secret key, many watermarking schemes embed watermarks which lie...

Straightforward adaptations of results for still images watermarking have led to non-secure video watermarking algorithms. The very specific nature of digital video has indeed to be considered so that robustness and security issues are handled efficiently. As a result, a novel video watermarking scheme is presented in this paper: security is achiev...

Recent efforts for watermarking digital video extend the results obtained for still image watermarking. As a result, most of the proposed algorithms rely on a frame-by-frame approach. Such an adaptation leads to unreliable algorithms in terms of security. The goal of this article is to stress the problem of collusion when digital watermarked data i...

Digital watermarking was introduced at the end of the 20th century to provide means of enforcing copyright protection once the use and distribution of digital multimedia data have exploded. This technology has first been intensively investigated for still images and recent efforts have been put to exhibit unifying characteristics. On the other hand...

Informed embedding is the practice of tailoring each watermarking pattern according to the cover Work in which it is to be embedded. The objective is to attain an optimal trade-off between estimates of perceptual fidelity and robustness. To date, our own studies of informed embedding have been limited to watermarks with very small data payloads. Ou...

During the last decade, a significant effort has been put into designing watermarking algorithms. The watermarking community now needs some advanced attacks and fair benchmarks in order to compare the performances of different watermarking technologies. Moreover, attacks permit the weaknesses of an algorithm to be found and consequently trigger fur...

Informed coding is the practice of representing watermark messages with patterns that are dependent on the cover works. This requires the use of a dirty-paper code, in which each message is represented by a large number of alternative vectors. Most previous dirty-paper codes are based on lattice codes, in which each code vector, or pattern, is a po...