Watermarking Procedure Research Articles

Image authentication with tampering localization based on watermark embedding in wavelet domain

An image authentication and tampering localization technique based on a wavelet-based digital watermarking procedure [Opt. Express 3(12), 491-496 (1998)] is proposed. To determine whether a given watermarked image has been tampered with or not, the similarity between the extracted and embedded watermarks is measured. If the similarity is less than a threshold value, the proposed sequential watermark alignment based on a coefficient stamping (SWACS) scheme is used to determine the modified wavelet coefficients corresponding to the tampered region. Then, the morphological region growing and subband duplication (MRGSD) scheme are used to include neighboring wavelet coefficients and then duplicate the wavelet coefficients in other subbands. The experimental results show that the proposed SWACS and MRGSD schemes can efficiently identify different types of image tampering. Moreover, the detection performance of the proposed system on various sizes of the watermark and tampered region is also evaluated.

A Bayesian Business Model for Video-Call Billing for End-to-End QoS Provision

Wireless communications and IP networks will evolve into a new converged vision, which is called ldquobeyond the third generation,rdquo where charging and billing will be essential tools for customer care to fight competition and to assure operator's revenue. This contribution proposes a business model for video-call billing founded on Bayes' decision testing. It is based on the end-to-end quality of service (QoS) estimated by exploiting the tracing watermarking procedure, which has recently been introduced into the literature. In particular, we employ the watermark embedded in each transmitted video sequence to monitor the QoS of the communication link and adequately charge the calling user, depending on the received video quality. Adopting such a Bayesian business model, we translate the network operator's paradigm of ldquo <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pay</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">as</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">you</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">talk</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(and</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">watch)</i> rdquo to ldquo <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">pay</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">how</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">you</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">talk</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(and</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">watch)</i> ,rdquo maximizing the operator's profit under a constrained video quality for end users. Wide simulation trials are conducted to characterize the effectiveness of the proposed method, using different business scenarios, confirming the validity of such an approach.

Robust watermarking procedure based on JPEG discrete cosine transform image compression

A new procedure for watermarking in the 88 block- based discrete cosine transform (DCT) domain (used for JPEG compression) is proposed. The influence of JPEG quantization on watermarked coefficients and on watermark is considered. The cri- terion for coefficients selection is derived, providing robustness for an arbitrary quantization degree. The modified form of coefficients probability density function (pdf) leads to the class of modified opti- mal detectors. Theoretical results are illustrated on various ex- amples. Efficiency of the proposed procedure is shown in the pres- ence of different quantization degrees, and other common attacks. © 2008 SPIE and IS&T. DOI: 10.1117/1.2981832

Watermarking sexually reproducing diploid organisms

DNA watermarks are used for hiding messages or for authenticating genetically modified organisms. Recently, we presented an algorithm called DNA-Crypt for generating DNA-based watermarks that can be integrated into the genome by using the characteristics of the degenerative genetic code. DNA-Crypt generates the watermark by replacing single bases and thus creating synonymous codons that encrypt the hidden information. Mutations within the integrated DNA sequence can be corrected using several mutation correction codes, to keep the hidden information intact. This method has successfully been tested in asexually replicating organisms like bacteria or yeast, where the watermark is duplicated with every cell division. It has been shown that DNA watermarks produced by DNA-Crypt do not influence the transcription or translation of a protein. In sexually reproducing diploid organisms, additional problems can occur, e.g. recombination events can destroy hidden information. Using population predictions as well as statistical analyses we identified a coupled Y-chromosomal/mitochondrial DNA watermarking procedure as the most appropriate for diploid organisms. We developed a mitochondria adapted version of DNA-Crypt, which is called Project Mito that can be used in combination with the original program. http://www.uni-muenster.de/Biologie.NeuroVer/Tumorbiologie/DNA-Crypt/index.html

Speech signals protection via logo watermarking based on the time–frequency analysis

A procedure for logo watermarking of speech signals is proposed. In order to take full advantage of both time and frequency domains, we have used joint time–frequency representation of speech signal, which provides a more comprehensive information compared to each domain individually. Time–frequency-based selection of the discrete Fourier transform coefficients is used for logo embedding. The proposed coefficients selection provides both the imperceptibility and robustness requirements. The binary logo is embedded by using the concept of bit-plane modification. The logo extraction procedure is provided as well. The robustness of the proposed procedure is tested under various attacks such as compression, noise addition, filtering, re-sampling, re-quantization, time stretch, pitch scaling, etc.

Watermarking Protocol for Web Context

Digital watermarking is considered to be a main technology for the copyright protection of multimedia digital content distributed on the Internet. However, watermarking procedures can effectively support copyright protection processes only if they are applied by employing specific watermarking protocols, which define the scheme of the interactions that have to take place among the entities involved in the content protection and web-based distribution. To this end, a number of current watermarking protocols can attain important achievements, such as the correct authentication of buyers without exposing their identities during web transactions and the capability of resorting to trusted watermark certification authorities to ensure a copyright protection process that is able to correctly take into account the rights of both buyers and sellers. However, these protocols are often not suitable for web context, where buyers are usually neither provided with digital certificates issued by trusted certification authorities nor able to autonomously perform complex security actions to purchase digital content distributed by web-based content providers. This paper presents an improved version of a web-oriented and interactive anonymous buyer-seller watermarking protocol previously presented by the author. The protocol overcomes the drawbacks affecting relevant protocols existing in literature, and is based on a design approach that makes it suitable for web contexts.

Web-oriented nonblind image watermarking procedure

The advances in multimedia and networking technologies have created opportunities for Internet pirates, who can copy digital contents and illegally distribute them, thus violating the legal rights of content owners. In such a situation, digital watermarking has gained popularity as a main technology to implement the copyright protection of multimedia digital contents distributed on the Internet. We present a novel "nonblind" watermarking procedure for JPEG images based on the use of protected extensible markup language (XML) documents. The procedure enables the copyright owner to insert a distinct watermark code identifying the buyer into the distributed images. Furthermore, to increase the security and robustness levels of the procedure, the watermark is repeatedly embedded into an image in the discrete cosine transform (DCT) domain at different frequencies and by exploiting both block classification techniques and perceptual analysis. The embedded watermark is then extracted from an image according to the information contained in a protected XML document that is associated to the image.

Hierarchical ownership and deterministic watermarking of digital images via polynomial interpolation

This paper presents a novel method for the secure management of digital images formulated within the mathematical theory of polynomial interpolation. As main innovative features, our approach is based on a hierarchical joint ownership of the image by a trusted layered authority and on a deterministic watermarking procedure, embedding a short meaningful or random signature into the image. Experimental results show that the inserted signature can almost always be fully recovered even in presence of a reasonable amount of image degradation due to image processing operators, such as filtering, geometric distortions and compression.

An Adaptive Compressed MPEG-2 Video Watermarking Scheme

Digital watermarking is becoming more and more important for protecting the authenticity of multimedia objects as they become easier to copy, exchange, and modify. Several watermarking schemes have been proposed in recent years, but most of them deal with still images, only some being extended over to the temporal domain for video watermarking. But again most of those approaches are applied to uncompressed video processing domain. In the subject paper, a new compressed video watermarking procedure is proposed. The developed method embeds several binary images, decomposed from a single watermark image, into different scenes of a video sequence. The spatial spread spectrum watermark is embedded directly into the compressed bit streams by modifying discrete cosine transform (DCT) coefficients. In order to embed the watermark with minimum loss in image fidelity, a visual mask based on local image characteristics is incorporated. Extensive experimental simulations demonstrate that the proposed watermarking scheme is substantially more effective and robust against spatial attacks such as scaling, rotation, frame averaging, and filtering, besides temporal attacks like frame dropping and temporal shifting.

A fragile watermark error detection scheme for wireless video communications

In video communications over error-prone channels, compressed video streams are extremely sensitive to bit errors. Often random and burst bit errors impede correct decoding of parts of a received bitstream. Video decoders normally utilize error concealment techniques to repair a damaged decoded frame, but the effectiveness of these error concealment schemes relies heavily on correctly locating errors in the bitstream. In this paper, we propose a fragile watermark-based error detection and localization scheme called "force even watermarking (FEW)". A fragile watermark is forced onto quantized DCT coefficients at the encoder. If at the decoder side the watermark is no longer intact, errors exist in the bitstream associated with a particular macro-block (MB). Thanks to the watermark, bitstream errors can accurately be located at MB level, which facilitates proper error concealment. This paper describes the algorithm, model and analysis of the watermarking procedure. Our simulation results show that compared to the syntax-based error detection schemes, the proposed FEW scheme significantly improves the error detection capabilities of the video decoder, while the peak signal-to-noise ratio loss and additional computational costs due to watermark embedding and extraction are small.

A Web Oriented Spread Spectrum Watermarking Procedure for MPEG-2 Videos

In the last decade digital watermarking procedures have become increasingly applied to implement the copyright protection of multimedia digital contents distributed on the Internet. To this end, it is worth noting that a lot of watermarking procedures for images and videos proposed in literature are based on spread spectrum techniques. However, some scepticism about the robustness and security of such watermarking procedures has arisen because of some documented attacks which claim to render the inserted watermarks undetectable. On the other hand, web content providers wish to exploit watermarking procedures characterized by flexible and efficient implementations and which can be easily integrated in their existing web services frameworks or platforms. This paper presents how a simple spread spectrum watermarking procedure for MPEG-2 videos can be modified to be exploited in web contexts. To this end, the proposed procedure has been made secure and robust against some well-known and dangerous attacks. Furthermore, its basic scheme has been optimized by making the insertion procedure adaptive with respect to the terminals used to open the videos and the network transactions carried out to deliver them to buyers. Finally, two different implementations of the procedure have been developed: the former is a high performance parallel implementation, whereas the latter is a portable Java and XML based implementation. Thus, the paper demonstrates that a simple spread spectrum watermarking procedure, with limited and appropriate modifications to the embedding scheme, can still represent a valid alternative to many other well-known and more recent watermarking procedures proposed in literature. Keywords— Copyright protection, digital watermarking, intellectual property protection.

Capacity of full frame DCT image watermarks

The evaluation of the number of bits that can be hidden within an image through digital watermarking is a crucial topic, which has been addressed only for additive watermarks. The evaluation of watermark capacity is very important because it allows to put a theoretical upper bound on the amount of information that can be hidden into an image by a given watermarking procedure, regardless of the watermark extraction technique. It is the purpose of this work to suggest a methodology for the evaluation of the watermark capacity in a nonadditive, non-Gaussian framework, and to discuss the results we obtained by applying it to a set of standard images.

Robust audio watermarking using perceptual masking

We present a watermarking procedure to embed copyright protection into digital audio by directly modifying the audio samples. Our audio-dependent watermarking procedure directly exploits temporal and frequency perceptual masking to guarantee that the embedded watermark is inaudible and robust. The watermark is constructed by breaking each audio clip into smaller segments and adding a perceptually shaped pseudo-random sequence. The noise-like watermark is statistically undetectable to prevent unauthorized removal. Furthermore, the author representation we introduce resolves the deadlock problem. We also introduce the notion of a dual watermark: one which uses the original signal during detection and one which does not. We show that the dual watermarking approach together with the procedure that we use to derive the watermarks effectively solves the deadlock problem. We also demonstrate the robustness of that watermarking procedure to audio degradations and distortions, e.g., those that result from colored noise, MPEG coding, multiple watermarks, and temporal resampling.

Resolving rightful ownerships with invisible watermarking techniques: limitations, attacks, and implications

Digital watermarks have been proposed as a means for copyright protection of multimedia data. We address the capability of invisible watermarking schemes to resolve copyright ownership. We show that, in certain applications, rightful ownership cannot be resolved by current watermarking schemes alone. Specifically, we attack existing techniques by providing counterfeit watermarking schemes that can be performed on a watermarked image to allow multiple claims of rightful ownership. In the absence of standardization and specific requirements imposed on watermarking procedures, anyone can claim ownership of any watermarked image. In order to protect against the counterfeiting techniques that we develop, we examine the properties necessary for resolving ownership via invisible watermarking. We introduce and study invertibility and quasi-invertibility of invisible watermarking techniques. We propose noninvertible watermarking schemes, and subsequently give examples of techniques that we believe to be nonquasi-invertible and hence invulnerable against more sophisticated attacks proposed in the paper. The attacks and results presented in the paper, and the remedies proposed, further imply that we have to carefully reevaluate the current approaches and techniques in invisible watermarking of digital images based on application domains, and rethink the promises, applications and implications of such digital means of copyright protection.

Multiresolution scene-based video watermarking using perceptual models

We present a watermarking procedure to embed copyright protection into digital video. Our watermarking procedure is scene-based and video dependent. It directly exploits spatial masking, frequency masking, and temporal properties to embed an invisible and robust watermark. The watermark consists of static and dynamic temporal components that are generated from a temporal wavelet transform of the video scenes. The resulting wavelet coefficient frames are modified by a perceptually shaped pseudorandom sequence representing the author. The noise-like watermark is statistically undetectable to thwart unauthorized removal. Furthermore, the author representation resolves the deadlock problem. The multiresolution watermark may be detected on single frames without knowledge of the location of the frames in the video scene. We demonstrate the robustness of the watermarking procedure to several video degradations and distortions.