Showing papers on "Watermark published in 1999"

Multimedia watermarking techniques

Abstract: Multimedia watermarking technology has evolved very quickly during the last few years. A digital watermark is information that is imperceptibly and robustly embedded in the host data such that it cannot be removed. A watermark typically contains information about the origin, status, or recipient of the host data. In this tutorial paper, the requirements and applications for watermarking are reviewed. Applications include copyright protection, data monitoring, and data tracking. The basic concepts of watermarking systems are outlined and illustrated with proposed watermarking methods for images, video, audio, text documents, and other media. Robustness and security aspects are discussed in detail. Finally, a few remarks are made about the state of the art and possible future developments in watermarking technology.

Hidden digital watermarks in images

Abstract: An image authentication technique by embedding digital "watermarks" into images is proposed. Watermarking is a technique for labeling digital pictures by hiding secret information into the images. Sophisticated watermark embedding is a potential method to discourage unauthorized copying or attest the origin of the images. In our approach, we embed the watermarks with visually recognizable patterns into the images by selectively modifying the middle-frequency parts of the image. Several variations of the proposed method are addressed. The experimental results show that the proposed technique successfully survives image processing operations, image cropping, and the Joint Photographic Experts Group (JPEG) lossy compression.

Spread spectrum image steganography

Abstract: We present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

Perceptual watermarks for digital images and video

Abstract: The growth of new imaging technologies has created a need for techniques that can be used for copyright protection of digital images and video. One approach for copyright protection is to introduce an invisible signal, known as a digital watermark, into an image or video sequence. In this paper, we describe digital watermarking techniques, known as perceptually based watermarks, that are designed to exploit aspects of the the human visual system in order to provide a transparent (invisible), yet robust watermark. In the most general sense, any watermarking technique that attempts to incorporate an invisible mark into an image is perceptually based. However, in order to provide transparency and robustness to attack, two conflicting requirements from a signal processing perspective, more sophisticated use of perceptual information in the watermarking process is required. We describe watermarking techniques ranging from simple schemes which incorporate common-sense rules in using perceptual information in the watermarking process, to more elaborate schemes which adapt to local image characteristics based on more formal perceptual models. This review is not meant to be exhaustive; its aim is to provide the reader with an understanding of how the techniques have been evolving as the requirements and applications become better defined.

Fair benchmark for image watermarking systems

Abstract: Since the early 90s a number of papers on 'robust' digital watermarking systems have been presented but none of them uses the same robustness criteria. This is not practical at all for comparison and slows down progress in this area. To address this issue, we present an evaluation procedure of image watermarking systems. First we identify all necessary parameters for proper benchmarking and investigate how to quantitatively describe the image degradation introduced by the watermarking process. For this, we show the weaknesses of usual image quality measures in the context watermarking and propose a novel measure adapted to the human visual system. Then we show how to efficiently evaluate the watermark performance in such a way that fair comparisons between different methods are possible. The usefulness of three graphs: 'attack vs. visual-quality,' 'bit-error vs. visual quality,' and 'bit-error vs. attack' are investigated. In addition the receiver operating characteristic (ROC) graphs are reviewed and proposed to describe statistical detection behavior of watermarking methods. Finally we review a number of attacks that any system should survive to be really useful and propose a benchmark and a set of different suitable images.

Digital watermarking for telltale tamper proofing and authentication

Abstract: In this paper, we consider the problem of digital watermarking to ensure the credibility of multimedia. We specifically address the problem of fragile digital watermarking for the tamper proofing of still images. Applications of our problem include authentication for courtroom evidence, insurance claims, and journalistic photography. We present a novel fragile watermarking approach which embeds a watermark in the discrete wavelet domain of the image by quantizing the corresponding coefficients. Tamper detection is possible in localized spatial and frequency regions. Unlike previously proposed techniques, this novel approach provides information on specific frequencies of the image that have been modified. This allows the user to make application-dependent decisions concerning whether an image, which is JPEG compressed for instance, still has credibility. Analysis is provided to evaluate the performance of the technique to varying system parameters. In addition, we compare the performance of the proposed method to existing fragile watermarking techniques to demonstrate the success and potential of the method for practical multimedia tamper proofing and authentication.

Perceptual watermarks for digital images and video

Abstract: The growth of new imaging technologies has created a need for techniques that can be used for copyright protection of digital images. One approach for copyright protection is to introduce an invisible signal known as a digital watermark in the image. In this paper, we describe digital image watermarking techniques known as perceptually watermarks that are designed to exploit aspects of the human visual system in order to produce a transparent, yet robust watermark.

Software watermarking: models and dynamic embeddings

Abstract: Watermarking embeds a secret message into a cover message. In media watermarking the secret is usually a copyright notice and the cover a digital image. Watermarking an object discourages intellectual property theft, or when such theft has occurred, allows us to prove ownership.The Software Watermarking problem can be described as follows. Embed a structure W into a program P such that: W can be reliably located and extracted from P even after P has been subjected to code transformations such as translation, optimization and obfuscation; W is stealthy; W has a high data rate; embedding W into P does not adversely affect the performance of P; and W has a mathematical property that allows us to argue that its presence in P is the result of deliberate actions.In the first part of the paper we construct an informal taxonomy of software watermarking techniques. In the second part we formalize these results. Finally, we propose a new software watermarking technique in which a dynamic graphic watermark is stored in the execution state of a program.

A Stochastic Approach to Content Adaptive Digital Image Watermarking

Abstract: This paper presents a new stochastic approach which can be applied with different watermark techniques. The approach is based on the computation of a Noise Visibility Function (NVF) that characterizes the local image properties, identifying textured and edge regions where the mark should be more strongly embedded. We present precise formulas for the NVF which enable a fast computation during the watermark encoding and decoding process. In order to determine the optimal NVF, we first consider the watermark as noise. Using a classical MAP image denoising approach, we show how to estimate the ”noise”. This leads to a general formulation for a texture masking function, that allows us to determine the optimal watermark locations and strength for the watermark embedding stage. We examine two such NVFs, based on either a non-stationary Gaussian model of the image, or a stationary Generalized Gaussian model. We show that the problem of the watermark estimation is equivalent to image denoising and derive content adaptive criteria. Results show that watermark visibility is noticeably decreased, while at the same time enhancing the energy of the watermark.

Robust mesh watermarking

Abstract: We describe a robust method for watermarking triangle meshes. Watermarking provides a mechanism for copyright protection of digital media by embedding information identifying the owner in the data. The bulk of the research on digital watermarks has focused on media such as images, video, audio, and text. Robust watermarks must be able to survive a variety of “attacks”, including resizing, cropping, and filtering. For resilience to such attacks, recent watermarking schemes employ a “spread-spectrum” approach – they transform the document to the frequency domain and perturb the coefficients of the perceptually most significant basis functions. We extend this spread-spectrum approach to work for the robust watermarking of arbitrary triangle meshes. Generalizing spread spectrum techniques to surfaces presents two major challenges. First, arbitrary surfaces lack a natural parametrization for frequency-based decomposition. Our solution is to construct a set of scalar basis function over the mesh vertices using multiresolution analysis. The watermark perturbs vertices along the direction of the surface normal, weighted by the basis functions. The second challenge is that simplification and other attacks may modify the connectivity of the mesh. We use an optimization technique to resample an attacked mesh using the original mesh connectivity. Results show that our watermarks are resistant to common mesh operations such as translation, rotation, scaling, cropping, smoothing, simplification, and resampling, as well as malicious attacks such as the insertion of noise, modification of low-order bits, or even insertion of other watermarks. CR Categories: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Surface Representations.

Digital authentication with analog documents

Abstract: Techniques for protecting the security of digital representations, and of analog forms made from them. The techniques include authentication techniques that can authenticate both a digital representation and an analog form produced from the digital representation, an active watermark that contains program code that may be executed when the watermark is read, and a watermark agent that reads watermarks and sends messages with information concerning the digital representations that contain the watermarks. The authentication techniques use semantic information to produce authentication information. Both the semantic information and the authentication information survive when an analog form is produced from the digital representation. In one embodiment, the semantic information is alphanumeric characters and the authentication information is either contained in a watermark embedded in the digital representation or expressed as a bar code. With the active watermark, the watermark includes program code. When a watermark reader reads the watermark, it may cause the program code to be executed. One application of active watermarks is making documents that send messages when they are operated on. A watermark agent may be either a permanent resident of a node in a network or of a device such as a copier or it may move from one network node to another. In the device or node, the watermark agent executes code which examines digital representations residing in the node or device for watermarked digital representations that are of interest to the watermark agent. The watermark agent then sends messages which report the results of its examination of the digital representations. If the watermarks are active, the agent and the active watermark may cooperate and the agent may cause some or all of the code that an active watermark contains to be executed.

Spread spectrum watermarking: malicious attacks and counterattacks

Abstract: Most watermarking methods for images and video have been proposed are based on ideas from spread spectrum radio communications, namely additive embedding of a (signal adaptive or non-adaptive) pseudo-noise watermark pattern, and watermark recovery by correlation. Even methods that are not presented as spread spectrum methods often build on these principles. Recently, some skepticism about the robustness of spread spectrum watermarks has arisen, specifically with the general availability of watermark attack software which claim to render most watermarks undetectable. In fact, spread spectrum watermarks and watermark detectors in their simplest form are vulnerable to a variety of attacks. However, with appropriate modifications to the embedding and extraction methods, spread spectrum methods can be made much more resistant against such attacks. In this paper, we review proposed attacks on spread spectrum watermarks are systematically. Further, modifications for watermark embedding and extraction are presented to avoid and counterattack these attacks. Important ingredients are, for example, to adapt the power spectrum of the watermark to the host signal power spectrum, and to employ an intelligent watermark detector with a block-wise multi-dimensional sliding correlator, which can recover the watermark even in the presence of geometric attacks.

Towards second generation watermarking schemes

Abstract: The digital watermarking schemes of today use pixels (samples in the case of audio), frequency or other transform coefficients to embed the information. The drawback of such schemes is that the watermark is not embedded in the perceptually significant portions of the data. We refer to such techniques as first generation watermarking schemes. In this paper we introduce the concept of second generation watermarking schemes which, unlike first generation watermarking schemes, employ the notion of data features. We propose a scheme based on point features in images using a scale interaction technique based on 2D continuous wavelets. The features are used to compute a Voronoi partition of the image. The watermark is embedded in each segment using spread spectrum watermarking. In the recovery process the same features are detected, and again used to partition the image. Then the watermark is extracted from each segment separately.

Video watermarking system for broadcast monitoring

Abstract: This paper presents a video watermarking technology for broadcast monitoring. The technology has been developed at the Philips Research Laboratories in Eindhoven in the context of the European ESPRIT project VIVA (Visual Identity Verification Auditor). The aim of the VIVA project is to investigate and demonstrate a professional broadcast surveillance system. The key technology in the VIVA project is a new video watermarking technique by the name of JAWS (Just Another Watermarking System). The JAWS system has been developed such that the embedded watermarks (1) are invisible, (2) are robust with respect to all common processing steps in the broadcast transmission chain, (3) have a very low probability of false alarms, (4) have a large payload at high rate, and (5) allow for a low complexity and a real-time detection. In this paper we present the basic ingredients of the JAWS technology. We also briefly discuss the performance of JAWS with respect to the requirements of broadcast monitoring.

Robust digital watermarking

Abstract: A watermarking procedure that is applicable to images, audio, video and multimedia data to be watermarked divides the data to be watermarked into a set of n×n blocks, such as the 8×8 blocks of MPEG. The same watermark signal can be distributed throughout the set of blocks in a large variety of ways. This allows the insertion algorithm to be changed without affecting the decoders. The decoding procedure first sums together the DCT coefficients of N sets of 8×8 blocks to form a set of N summed 8×8 blocks and then extracts the watermark from the summed block. Since the sum of the DCT blocks is equal to the DCT of the sum of the intensity blocks, efficient decoding can occur in both the spatial and frequency domains. The symmetric nature of the decoding process allows geometric distortions to be handled in the spatial domain and other signal distortions to be handled in the frequency domain. Moreover, insertion of a watermark signal into image data and the subsequent extraction of the watermark from watermarked image data which has been subject to distortion between the times of insertion and extraction involves the insertion of multiple watermarks designed to survive predefined distortions of the image data, such as panscan or letterbox mode transformations. Alternatively, a registration pattern in the image data, after the image data containing the registration pattern is subject to an unknown distortion, is used to compensate for distortion of the watermarked image data.

Watermark detection using a fourier mellin transform

Abstract: A watermark detector maps target media data into a log polar coordinate system and correlates the target media with a detection watermark to compute orientation parameters. The correlation process computes a measure of correlation for an array of potential orientation parameter candidates. Evaluating the correlation associated with these candidates, the detector selects one or more of the orientation parameters. It then proceeds to refine the correlation by using the computed orientation parameters, namely scale and rotation, to find additional parameters such as translation and differential scale.

Watermarking resistance to translation, rotation, and scaling

Abstract: In this paper we propose a new watermarking scheme for digital images that allows watermark recovery even if the image has been subjected to generalized geometrical transforms. The watermark is given by a binary number and every watermark bit is represented by a 2D function. The functions are weighted, using a mask that is proportional to the luminance, and then modulated onto the blue component of the image. To recover an embedded bit, the embedded watermark is estimated using a prediction filter. The sign of the correlation between the estimated watermark and the original function determine the embedded several times at horizontally and vertically shifted locations. In the watermark recovery process we first compute a prediction of the embedded watermark. Then the autocorrelation function is computed for this prediction. The multiple embedding of the watermark result in additional autocorrelation peaks. By comparing the configuration of the extracted peaks with their expected configuration we can determine the affine distortion applied to the image. The distortion can then be inverted and the watermark recovered in a standard way.

The use of watermarks in the protection of digital multimedia products

Abstract: The watermarking of digital images, audio, video, and multimedia products in general has been proposed for resolving copyright ownership and verifying originality of content. This paper studies the contribution of watermarking for developing protection schemes. A general watermarking framework (GWF) is studied and the fundamental demands are listed. The watermarking algorithms, namely watermark generation, embedding, and detection, are analyzed and necessary conditions for a reliable and efficient protection are stated. Although the GWF satisfies the majority of requirements for copyright protection and content verification, there are unsolved problems inside a pure watermarking framework. Particular solutions, based on product registration and related network services, are suggested to overcome such problems.

Secure distribution of digital representations

Abstract: Techniques for secure distribution of digital representations that combine encryption and watermarking. When a user at a client desires to download a digital representation, the user makes a request to a server for the digital representation, which encrypts the digital representation using a first key and downloads the encrypted digital representation to the user. Before the user performs any operation on the decrypted digital representation, a secret fingerprint watermark identifying the user is added to the digital representation. The fingerprint watermark is added either at the server or at the client and a copy of the fingerprinted digital representation is kept at the server. If the user makes an impermissible use of the digital representation, the secret fingerprint watermark can be used to identify the user. The request made by the user indicates the type of use that the user whished to make of the digital representation. If the use involves storage of the digital representation at the client, the server provides a second key that the client employs to encrypt the digital representation. If the user has permission to do so, the user may modify the digital representation and return the modified digital representation to the server for further distribution. In this case, the second key is used to encrypt the digital representation when it is sent to the server. The second key also serves as the user identification in the fingerprint watermark. If the user loses the second key, it can be recovered from the copy of the fingerprinted digital representation kept at the server. The first and second keys and any decrypted copy of the digital representation are kept in secure storage in the client.

Images with self-correcting capabilities

Abstract: In this paper, we introduce two techniques for self-embedding an image in itself as a means for protecting the image content. After self-embedding, it is possible to recover portions of the image that have been cropped out, replaced, damaged, or otherwise tampered without accessing the original image. The first method is based on transforming small 8/spl times/8 blocks using a DCT, quantizing the coefficients, and carefully encoding them in the least significant bits of other, distant squares. This method provides very high quality of reconstruction but it is very fragile. The quality of the reconstructed image areas is roughly equivalent to a 50% quality JPEG compressed original. The second method uses a principle similar to differential encoding to embed a circular shift of the original image with decreased color depth into the original image. The quality of the reconstructed image gradually degrades with increasing amount of noise in the tampered image. The first technique can also be used as a fragile watermark for image authentication, while the second technique can be classified as a semi-robust watermark.

The use of watermarks in the protection of digital multimedia products : Identification and protection of multimedia information

Abstract: The watermarking of digital images, audio, video, and multimedia products in general has been proposed for resolving copyright ownership and verifying originality of content. This paper studies the contribution of watermarking for developing protection schemes. A general watermarking framework (GWF) is studied and the fundamental demands are listed. The watermarking algorithms, namely watermark generation, embedding, and detection, are analyzed and necessary conditions for a reliable and efficient protection are stated. Although the GWF satisfies the majority of requirements for copyright protection and content verification, there are unsolved problems inside a pure watermarking framework. Particular solutions, based on product registration and related network services, are suggested to overcome such problems.

A statistical watermark detection technique without using original images for resolving rightful ownerships of digital images

Abstract: Digital watermarking has been proposed as the means for copyright protection of multimedia data. Many of existing watermarking schemes focused on the robust means to mark an image invisibly without really addressing the ends of these schemes. This paper first discusses some scenarios in which many current watermarking schemes fail to resolve the rightful ownership of an image. The key problems are then identified, and some crucial requirements for a valid invisible watermark detection are discussed. In particular, we show that, for the particular application of resolving rightful ownership using invisible watermarks, it might be crucial to require that the original image not be directly involved in the watermark detection process. A general framework for validly detecting the invisible watermarks is then proposed. Some requirements on the claimed signature/watermarks to be used for detection are discussed to prevent the existence of any counterfeit scheme. The optimal detection strategy within the framework is derived. We show the effectiveness of this technique based on some visual-model-based watermark encoding schemes.

Statistical analysis of watermarking schemes for copyright protection of images

Abstract: In this paper, we address the problem of the performance analysis of image watermarking systems that do not require the availability of the original image during ownership verification. We focus on a statistical approach to obtain models that can serve as a basis for the application of decision theory to the design of efficient detector structures. Special attention is paid to the possible nonexistence of a statistical description of the original image. Different modeling approaches are proposed for the cases when such a statistical characterization is known and when it is not. Watermarks may encode a message, and the performance of the watermarking system is evaluated using as a measure the probability of false alarm, the probability of detection when the presence of the watermark is tested, and the probability of error when the information that it carries is extracted. Finally, the modeling techniques studied are applied to the analysis of two watermarking schemes, one of them defined in the spatial domain, and the other in the direct cosine transform (DCT) domain. The theoretical results are contrasted with empirical data obtained through experimentation covering several cases of interest. We show how choosing an appropriate statistical model for the original image can lead to considerable improvements in performance.

Template based recovery of Fourier-based watermarks using log-polar and log-log maps

Abstract: Digital watermarks have been proposed as a method for discouraging illicit copying and distribution of copyrighted material. The paper describes a method for the secure and robust copyright protection of digital images. We present an approach for embedding a digital watermark into an image using the fast Fourier transform. To this watermark is added a template in the Fourier transform domain, to render the method robust against rotations and scaling, or aspect ratio changes. We detail an algorithm based on the log-polar or log-log maps for the accurate and efficient recovery of the template in a rotated and scaled image. We also present results which demonstrate the robustness of the method against some common image processing operations such as compression, rotation, scaling and aspect ratio changes.

Method for data preparation and watermark insertion

Abstract: A method for data preparation and watermark insertion. The method includes the step of preparing the data at a first time by manipulating at least one set of the data characteristics (306) for subsequent insertion of a first watermark (2). In a preferred embodiment of the method of the present invention the method further includes the step of inserting the first watermark by manipulating the set of data characteristics at a second time subsequent to the first time. In a variation of the present invention a method for inserting a watermark into compressed data is provided. The compressed data has sets of data characteristics. The method includes the steps of inserting a watermark by manipulating the set of data characteristics; and optimizing the manipulated data by modifying the compressed data characteristics subject to a set of constraints (308, 310).

Multiresolution watermarking for images and video

Abstract: This paper proposes a unified approach to digital watermarking of images and video based on the two- and three-dimensional discrete wavelet transforms. The hierarchical nature of the wavelet representation allows multiresolutional detection of the digital watermark, which is a Gaussian distributed random vector added to all the high-pass bands in the wavelet domain. We show that when subjected to distortion from compression or image halftoning, the corresponding watermark can still be correctly identified at each resolution (excluding the lowest one) in the wavelet domain. Computational savings from such a multiresolution watermarking framework is obvious, especially for the video case.

Robust 3D DFT Video Watermarking

Abstract: This paper proposes a new approach for digital watermarking and secure copyright protection of videos, the principal aim being to discourage illicit copying and distribution of copyrighted material. The method presented here is based on the discrete Fourier transform (DFT) of three dimensional chunks of video scene, in contrast with previous works on video watermarking where each video frame was marked separately, or where only intra-frame or motion compensation parameters were marked in MPEG compressed videos. Two kinds of information are hidden in the video: a watermark and a template. Both are encoded using an owner key to ensure the system security and are embedded in the 3D DFT magnitude of video chunks. The watermark is a copyright information encoded in the form of a spread spectrum signal. The template is a key based grid and is used to detect and invert the effect of frame-rate changes, aspect-ratio modification and rescaling of frames. The template search and matching is performed in the log-log-log map of the 3D DFT magnitude. The performance of the presented technique is evaluated experimentally and compared with a frame-by-frame 2D DFT watermarking approach.

A Review of Data Hiding in Digital Images.

Abstract: In this paper we will overview the use of data hiding techniques in digital images. In particular we will describe how one can use Steganography to hide information in a digital image. Steganography is related to cryptography and is the basis for many of the digital watermarking techniques currently being developed. The interest in data hiding has risen with the recent activity in digital copyright protection schemes. One way to protect the ownership of a digital image is to secretly embed data in the content of the image identifying the owner. This paper will review recent developments in data hiding, specifically as it pertains to copyright protection of digital images.

Passive and active software objects containing bore resistant watermarking

Abstract: A technique for imparting substantial break-once-run-everywhere (BORE) resistance to passive and active software objects, and for controlling access and use of resulting protected objects by a client computer (400). Specifically, a relatively large number, n, of identical watermarks (1720) are embedded throughout a software object (1700), through use of n different secret watermark keys to form a protected object, with each key defining a pointer to a location in the protected object at which a corresponding watermark appears. Once a user has downloaded a protected object through a client computer, the user transacts with a publisher's web server (335) to obtain an electronic license, cryptographically signed by the publisher to an enforcer (600, 600′) located in that client computer, which specifies rights, which the publisher accords, for accessing and using this object, to this computer and an “expected” value of a parameter contained in the watermarks. The enforcer is equipped with only one of the n watermark keys. Whenever the client computer attempts to access a file containing the protected object, the enforcer examines the object using its secret watermark key. If the object contains a watermark appearing at a location specified by the enforcer's watermark key, a digital rights management system (456) executing in a client operating system (454) accesses a license database (570) to determine whether a signed license made to the enforcer and linked, via the publisher's cryptographic signature, to this protected object resides in that database. If no such license exists, the enforcer inhibits any further access to the object. Otherwise, the enforcer determines whether: the “expected” parameter value matches an actual value for the same parameter detected in a watermark contained in the object, and the license is signed by the vendor whose identification is embedded in the watermark; and, if so, permits access to the object in accordance with the rights specified in the license.

Data processing apparatus and method and storage medium

Abstract: This invention provides a technique capable of always keeping digital watermark information embedded in image data having the embedded digital watermark information by an optimum scheme on the basis of a time factor, or removing a digital watermark, or erasing the image data. An apparatus for achieving the above object has functions of holding image data having additional information embedded as a digital watermark, detecting time information related to the image data, and changing the embedding scheme for the additional information as the digital watermark embedded in the image data on the basis of the detected time information.