Showing papers on "Digital watermarking published in 2007"

Digital Watermarking and Steganography

Abstract: Digital audio, video, images, and documents are flying through cyberspace to their respective owners. Unfortunately, along the way, individuals may choose to intervene and take this content for themselves. Digital watermarking and steganography technology greatly reduces the instances of this by limiting or eliminating the ability of third parties to decipher the content that he has taken. The many techiniques of digital watermarking (embedding a code) and steganography (hiding information) continue to evolve as applications that necessitate them do the same. The authors of this second edition provide an update on the framework for applying these techniques that they provided researchers and professionals in the first well-received edition. Steganography and steganalysis (the art of detecting hidden information) have been added to a robust treatment of digital watermarking, as many in each field research and deal with the other. New material includes watermarking with side information, QIM, and dirty-paper codes. The revision and inclusion of new material by these influential authors has created a must-own book for anyone in this profession. *This new edition now contains essential information on steganalysis and steganography *New concepts and new applications including QIM introduced *Digital watermark embedding is given a complete update with new processes and applications

Expansion Embedding Techniques for Reversible Watermarking

Abstract: Reversible watermarking enables the embedding of useful information in a host signal without any loss of host information. Tian's difference-expansion technique is a high-capacity, reversible method for data embedding. However, the method suffers from undesirable distortion at low embedding capacities and lack of capacity control due to the need for embedding a location map. We propose a histogram shifting technique as an alternative to embedding the location map. The proposed technique improves the distortion performance at low embedding capacities and mitigates the capacity control problem. We also propose a reversible data-embedding technique called prediction-error expansion. This new technique better exploits the correlation inherent in the neighborhood of a pixel than the difference-expansion scheme. Prediction-error expansion and histogram shifting combine to form an effective method for data embedding. The experimental results for many standard test images show that prediction-error expansion doubles the maximum embedding capacity when compared to difference expansion. There is also a significant improvement in the quality of the watermarked image, especially at moderate embedding capacities

Method and system for digital watermarking

Abstract: A method for applying a digital watermark to a content signal is disclosed. In accordance with such a method, a watermarking key is identified. The watermarking key includes a binary sequence and information describing application of that binary sequence to the content signal. The digital watermark is then encoded within the content signal at one or more locations determined by the watermarking key.

Reversible Image Watermarking Based on Integer-to-Integer Wavelet Transform

Abstract: This paper proposes a high capacity reversible image watermarking scheme based on integer-to-integer wavelet transforms. The proposed scheme divides an input image into nonoverlapping blocks and embeds a watermark into the high-frequency wavelet coefficients of each block. The conditions to avoid both underflow and overflow in the spatial domain are derived for an arbitrary wavelet and block size. The payload to be embedded includes not only messages but also side information used to reconstruct the exact original image. To minimize the mean-squared distortion between the original and the watermarked images given a payload, the watermark is adaptively embedded into the image. The experimental results show that the proposed scheme achieves higher embedding capacity while maintaining distortion at a lower level than the existing reversible watermarking schemes.

Coding Algorithms for 3DTV—A Survey

Abstract: Research efforts on 3DTV technology have been strengthened worldwide recently, covering the whole media processing chain from capture to display. Different 3DTV systems rely on different 3D scene representations that integrate various types of data. Efficient coding of these data is crucial for the success of 3DTV. Compression of pixel-type data including stereo video, multiview video, and associated depth or disparity maps extends available principles of classical video coding. Powerful algorithms and open international standards for multiview video coding and coding of video plus depth data are available and under development, which will provide the basis for introduction of various 3DTV systems and services in the near future. Compression of 3D mesh models has also reached a high level of maturity. For static geometry, a variety of powerful algorithms are available to efficiently compress vertices and connectivity. Compression of dynamic 3D geometry is currently a more active field of research. Temporal prediction is an important mechanism to remove redundancy from animated 3D mesh sequences. Error resilience is important for transmission of data over error prone channels, and multiple description coding (MDC) is a suitable way to protect data. MDC of still images and 2D video has already been widely studied, whereas multiview video and 3D meshes have been addressed only recently. Intellectual property protection of 3D data by watermarking is a pioneering research area as well. The 3D watermarking methods in the literature are classified into three groups, considering the dimensions of the main components of scene representations and the resulting components after applying the algorithm. In general, 3DTV coding technology is maturating. Systems and services may enter the market in the near future. However, the research area is relatively young compared to coding of other types of media. Therefore, there is still a lot of room for improvement and new development of algorithms.

Very Fast Watermarking by Reversible Contrast Mapping

Abstract: Reversible contrast mapping (RCM) is a simple integer transform that applies to pairs of pixels. For some pairs of pixels, RCM is invertible, even if the least significant bits (LSBs) of the transformed pixels are lost. The data space occupied by the LSBs is suitable for data hiding. The embedded information bit-rates of the proposed spatial domain reversible watermarking scheme are close to the highest bit-rates reported so far. The scheme does not need additional data compression, and, in terms of mathematical complexity, it appears to be the lowest complexity one proposed up to now. A very fast lookup table implementation is proposed. Robustness against cropping can be ensured as well

Combined DWT-DCT Digital Image Watermarking

Abstract: The proliferation of digitized media due to the rapid growth of networked multimedia systems, has created an urgent need for copyright enforcement technologies that can protect copyright ownership of multimedia objects. Digital image watermarking is one such technology that has been developed to protect digital images from illegal manipulations. In particular, digital image watermarking algorithms which are based on the discrete wavelet transform have been widely recognized to be more prevalent than others. This is due to the wavelets' excellent spatial localization, frequency spread, and multi-resolution characteristics, which are similar to the theoretical models of the human visual system. In this paper, we describe an imperceptible and a robust combined DWT-DCT digital image watermarking algorithm. The algorithm watermarks a given digital image using a combination of the Discrete Wavelet Transform (DWT) and the Discrete Cosine Transform (DCT). Performance evaluation results show that combining the two transforms improved the performance of the watermarking algorithms that are based solely on the DWT transform.

Digital Watermarking and Steganography: Fundamentals and Techniques

Abstract: In addition to providing students, researchers, and other professionals with mechanical information regarding digital watermarking and steganography, this work also provides them with the framework needed to develop extensive advanced algorithms. It shows how robust high-capacity watermarking techniques can be successfully used to enlarge the hiding capacity while maintaining the robustness of the watermark. Several robust algorithms are presented to illustrate the framework and provide assistance in understanding and implementing fundamental principles. Alternatives to traditional strategies are presented. The principles taught are illustrated with plentiful graphs and examples in order to simplify the problems and make highly complicated theories readily understandable.

Commutative Encryption and Watermarking in Video Compression

Abstract: A scheme is proposed to implement commutative video encryption and watermarking during advanced video coding process. In H.264/AVC compression, the intra-prediction mode, motion vector difference and discrete cosine transform (DCT) coefficients' signs are encrypted, while DCT coefficients' amplitudes are watermarked adaptively. To avoid that the watermarking operation affects the decryption operation, a traditional watermarking algorithm is modified. The encryption and watermarking operations are commutative. Thus, the watermark can be extracted from the encrypted videos, and the encrypted videos can be re-watermarked. This scheme embeds the watermark without exposing video content's confidentiality, and provides a solution for signal processing in encrypted domain. Additionally, it increases the operation efficiency, since the encrypted video can be watermarked without decryption. These properties make the scheme a good choice for secure media transmission or distribution

Digital watermarking apparatus and methods

Abstract: The present invention relates to various digital watermarking methods, apparatus and systems. One claim recites a method of determining a size or denomination of a momentary object. The method includes: utilizing a configured, multi-purpose electronic processor, decoding a digital watermark embedded in a monetary object, the watermark including data corresponding to a denomination of the monetary object; based on the data, determining feedback to indicate the denomination of the monetary object; and providing the feedback. Handheld computing devices can be advantageously employed with this combination. Of course, other combinations are provided and claimed.

An Oblivious Watermarking for 3-D Polygonal Meshes Using Distribution of Vertex Norms

Abstract: Although it has been known that oblivious (or blind) watermarking schemes are less robust than nonoblivious ones, they are more useful for various applications where a host signal is not available in the watermark detection procedure. From a viewpoint of oblivious watermarking for a three-dimensional (3-D) polygonal mesh model, distortionless attacks, such as similarity transforms and vertex reordering, might be more serious than distortion attacks including adding noise, smoothing, simplification, remeshing, clipping, and so on. Clearly, it is required to develop an oblivious watermarking that is robust against distortionless as well as distortion attacks. In this paper, we propose two oblivious watermarking methods for 3-D polygonal mesh models, which modify the distribution of vertex norms according to the watermark bit to be embedded. One method is to shift the mean value of the distribution and another is to change its variance. Histogram mapping functions are introduced to modify the distribution. These mapping functions are devised to reduce the visibility of watermark as much as possible. Since the statistical features of vertex norms are invariant to the distortionless attacks, the proposed methods are robust against such attacks. In addition, our methods employ an oblivious watermark detection scheme, which can extract the watermark without referring to the cover mesh model. Through simulations, we demonstrate that the proposed approaches are remarkably robust against distortionless attacks. In addition, they are fairly robust against various distortion attacks

A survey of RST invariant image watermarking algorithms

Abstract: In this article, we review the algorithms for rotation, scaling and translation (RST) invariant image watermarking. There are mainly two categories of RST invariant image watermarking algorithms. One is to rectify the RST transformed image before conducting watermark detection. Another is to embed and detect watermark in an RST invariant or semi-invariant domain. In order to help readers understand, we first introduce the fundamental theories and techniques used in the existing RST invariant image watermarking algorithms. Then, we discuss in detail the work principles, embedding process, and detection process of the typical RST invariant image watermarking algorithms. Finally, we analyze and evaluate these typical algorithms through implementation, and point out their advantages and disadvantages.

Histogram-Based Audio Watermarking Against Time-Scale Modification and Cropping Attacks

Abstract: In audio watermarking area, the robustness against desynchronization attacks, such as TSM (Time-Scale Modification) and random cropping operations, is still one of the most challenging issues. In this paper, we present a multibit robust audio watermarking solution for such a problem by using the insensitivity of the audio histogram shape and the modified mean to TSM and cropping operations. We address the insensitivity property in both mathematical analysis and experimental testing by representing the histogram shape as the relative relations in the number of samples among groups of three neighboring bins. By reassigning the number of samples in groups of three neighboring bins, the watermark sequence is successfully embedded. In the embedding process, the histogram is extracted from a selected amplitude range by referring to the mean in such a way that the watermark will be able to be resistant to amplitude scaling and avoid exhaustive search in the extraction process. The watermarked audio signal is perceptibly similar to the original one. Experimental results demonstrate that the hidden message is very robust to TSM and random cropping attacks, and also has a satisfactory robustness for those common audio signal processing operations.

Digital Audio Watermarking Techniques and Technologies: Applications and Benchmarks

Abstract: "Digital audio watermarking has been proposed as a new and alternative method to enforce intellectual property rights and protect digital audio from tampering. Digital Audio Watermarking Techniques and Technologies: Applications and Benchmarks is a comprehensive compilation of the major theoretical frameworks, research findings, and practical applications. With inclusive coverage of the most authoritative research in the area, Digital Audio Watermarking Techniques and Technologies: Applications and Benchmarks will serve as a vital reference to researchers and practitioners in a variety of disciplines, including engineering, information technology, and digital audio. With value to a diverse range of users, this Premier Reference Source suits libraries in numerous settings."

A Framework for Robust Watermarking of H.264-Encoded Video With Controllable Detection Performance

Abstract: As H.264 digital video becomes more prevalent, the need for copyright protection and authentication methods that are appropriate for this standard will emerge. This paper proposes a robust watermarking algorithm for H.264. We employ a human visual model adapted for a 4 times 4 discrete cosine transform block to increase the payload and robustness while limiting visual distortion. A key-dependent algorithm is used to select a subset of the coefficients that have visual watermarking capacity. Furthermore, the watermark is spread over frequencies and within blocks to avoid error pooling. This increases the payload and robustness without noticeably changing the perceptual quality. We embed the watermark in the coded residuals to avoid decompressing the video; however, we detect the watermark from the decoded video sequence in order to make the algorithm robust to intraprediction mode changes. We build a theoretical framework for watermark detection based on a likelihood ratio test. This framework is used to obtain optimal video watermark detection with controllable detection performance. Our simulation results show that we achieve the desired detection performance in Monte Carlo trials. We demonstrate the robustness of our proposed algorithm to several different attacks

Pattern-Based Data Hiding for Binary Image Authentication by Connectivity-Preserving

Abstract: In this paper, a novel blind data hiding method for binary images authentication aims at preserving the connectivity of pixels in a local neighborhood is proposed. The "flippability" of a pixel is determined by imposing three transition criteria in a 3 times 3 moving window centered at the pixel. The "embeddability" of a block is invariant in the watermark embedding process, hence the watermark can be extracted without referring to the original image. The "uneven embeddability" of the host image is handled by embedding the watermark only in those "embeddable" blocks. The locations are chosen in such a way that the visual quality of the watermarked image is guaranteed. Different types of blocks are studied and their abilities to increase the capacity are compared. The problem of how to locate the "embeddable" pixels in a block for different block schemes is addressed which facilitates the incorporation of the cryptographic signature as the hard authenticator watermark to ensure integrity and authenticity of the image. Discussions on the security considerations, visual quality against capacity, counter measures against steganalysis and analysis of the computational load are provided. Comparisons with prior methods show superiority of the proposed scheme

Robust Video Watermarking of H.264/AVC

Abstract: A robust video watermarking scheme of the state-of-the-art video coding standard H.264/AVC is proposed in this brief. 2-D 8-bit watermarks such as detailed company trademarks or logos can be used as inconvertible watermark for copyright protection. A grayscale watermark pattern is first modified to accommodate the H.264/AVC computational constraints, and then embedded into video data in the compressed domain. With the proposed method, the video watermarking scheme can achieve high robustness and good visual quality without increasing the overall bit-rate. Experimental results show that our algorithm can robustly survive transcoding process and strong common signal processing attacks, such as bit-rate reduction, Gaussian filtering and contrast enhancement

Watermarked 3-D Mesh Quality Assessment

Abstract: This paper addresses the problem of assessing distortions produced by watermarking 3D meshes. In particular, a new methodology for subjective evaluation of the quality of 3D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict the perceptual impact of 3D watermarking is assessed and compared with the state of the art. Results obtained show good correlations between the proposed objective metrics and subjective assessments by human observers

High capacity lossless data hiding based on histogram modification

Abstract: This letter introduces a lossless reversible data hiding method. The original image is recovered without any distortion from the marked image following the extraction of the hidden data. The main algorithm is based on the relocation of zeros (or minima) and peaks of the histograms of the blocks of the original image to embed the data. It leads to the modification of the grey values of some pixels. It can embed more data than many of the existing reversible data hiding algorithms.The PSNR of the proposed method is better than many of the existing reversible data hiding techniques. Some of the huge experimental results are presented to prove its validity.

Detecting media areas likely of hosting watermarks

Abstract: The present invention relates generally to digital watermarking and steganographic encoding. One claim recites a method including: receiving data corresponding to at least a portion of digital data; separating the data into a plurality of portions; determining a measure relative to a predetermined measure for each of the portions, wherein the measure comprises a measure related to a predetermined digital watermark signal; based at least in part on the measure, identifying which out of the plurality of portions are likely to host digital watermarking therein. Of course, other combinations are provided as well.

Natural language watermarking

Abstract: A method, system and machine-readable medium are provided for watermarking natural language digital text. A deep structure may be generated and a group of features may be extracted from natural language digital text input. The deep structure may be modified based, at least pardy, on a watermark. Natural language digital text output may be generated based on die modified deep structure.

Adaptive DWT-SVD Domain Image Watermarking Using Human Visual Model

Abstract: As digital watermarking has become an important tool for copyright protection, various watermarking schemes have been proposed in literature. Among them both discrete wavelet transform (DWT) and singular value decomposition (SVD) are commonly used. In a DWT-based watermarking scheme, the host image is decomposed into four frequency bands, and DWT coefficients in each band are modified to hide watermark information. Modification in all frequencies enables watermarking schemes using DWT robust to a wide range of attacks. However, as most transform methods, DWT decomposes images in terms of a standard basis set which is not necessarily optimal for a given image. By contrast with DWT, SVD offers a tailor-made basis for a given image which packs maximum signal energy into as few coefficients as possible. SVD is used in image processing also for its properties of stability, proportion invariance and rotation invariance. In this paper we propose a hybrid DWT-SVD domain watermarking scheme considering human visual properties. After decomposing the host image into four subbands, we apply SVD to each subband and embed singular values of the watermark into them. The embedding strength is determined by a human visual model proposed in A.S. Lewis and G. Knowles, (1992) and improved in M. Bertran et al., (2001). Our scheme has advantages of robustness for its embedding data into all frequencies and large capacity for using SVD. In addition, the use of human visual model guarantees the imperceptibility of the watermark.

An image fragile watermark scheme based on chaotic image pattern and pixel-pairs

Abstract: Fragile watermarking techniques for digital content have been studied in the past few years. Fragile watermarks are used to determine if a piece of watermarked digital content has been tampered, and distinguish tampered areas from non-tampered areas without referring to the original digital content. In this paper, a general framework for fragile watermark is proposed, and then a novel fragile watermarking scheme for image authentication is presented. The embedding process of fragile watermark starts from computing the difference image between the host image and its chaotic pattern. followed by mapping the difference image into a binary image. The binary image is then inserted into the least significant bit (LSB) bitplane of the host image. In addition, chaotic map is used to generate the chaotic pattern image, which can be used as secret key to improve the security of watermark algorithm. Due to employing permutation transform and chaotic image pattern, the corresponding position relation is broken between pixels in the watermarked image and the watermark. Simulation results and performance analysis show that the presented method is fast, secure and capable of detecting and localizing modification.

Statistical Fragile Watermarking Capable of Locating Individual Tampered Pixels

Abstract: Capability of accurately locating tampered pixels is desirable in image authentication. We propose a novel statistical scheme of fragile watermarking, in which a set of tailor-made authentication data for each pixel together with some additional test data are embedded into the host image. On the authentication side, examining the pixels and their corresponding authentication data will reveal the exact pattern of the content modification. As long as the tampered area is not too extensive, two distinct probability distributions corresponding to tampered and original pixels can be used to exactly identify the tampered pixels.