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Showing papers on "Watermark published in 2011"


Journal ArticleDOI
TL;DR: A robust digital image watermarking scheme based on singular value decomposition (SVD) and a tiny genetic algorithm (Tiny-GA) and Experimental results demonstrate that the scheme is able to withstand a variety of image processing attacks.

167 citations


Journal ArticleDOI
TL;DR: Experimental results show that the proposed watermarking method is comparable to, if not, better than SVD based method and several selected typical audioWatermarking methods, even in the presence of various common signal processing attacks.

160 citations


Journal ArticleDOI
TL;DR: The lower the tampering rate, the more levels of content data are recovered, and the better the quality of restored results.
Abstract: This paper proposes two novel self-embedding watermarking schemes based upon a reference sharing mechanism, in which the watermark to be embedded is a reference derived from the original principal content in different regions and shared by these regions for content restoration. After identifying tampered blocks, both the reference data and the original content in the reserved area are used to recover the principal content in the tampered area. By using the first scheme, the original data in five most significant bit layers of a cover image can be recovered and the original watermarked image can also be retrieved when the content replacement is not too extensive. In the second scheme, the host content is decomposed into three levels, and the reference sharing methods with different restoration capabilities are employed to protect the data at different levels. Therefore, the lower the tampering rate, the more levels of content data are recovered, and the better the quality of restored results.

151 citations


Book ChapterDOI
23 Oct 2011
TL;DR: Experimental results demonstrate that the proposed LWT-SVD method is not only robust to both general signal processing and desynchronization attacks but also outperform the selected previous studies.
Abstract: In this paper, a new and robust audio watermarking scheme based on lifting wavelet transform (LWT) and singular value decomposition (SVD) is proposed. Specifically, the watermark data is inserted in the LWT coefficients of the low frequency subband taking advantage of SVD and quantization index modulation (QIM). The use of QIM renders our scheme blind in nature. Furthermore, the synchronization code technique is also integrated with hybrid LWT-SVD audio watermarking. Experimental results demonstrate that the proposed LWT-SVD method is not only robust to both general signal processing and desynchronization attacks but also outperform the selected previous studies.

143 citations


Journal ArticleDOI
TL;DR: Experimental results demonstrate that the proposed chaos based watermarking scheme is not only secure but also achieves superior tamper detection and localization accuracy under different attacks.
Abstract: In the past few years, various fragile watermarking techniques have been proposed for image authentication and tamper detection. In this paper, a novel chaos based watermarking scheme for image authentication and tamper detection is proposed. Tamper localization and detection accuracy are two important aspects of the authentication watermarking schemes. Our scheme can detect any modification made to the image and can also indicate the specific locations that have been modified. To improve the security of the proposed scheme two chaotic maps are employed. Since chaotic maps are sensitive to initial values, the corresponding position relation between pixels in the watermarked image and the watermark get disturbed, which helps the watermarking scheme to withstand counterfeiting attacks. Initial values of the chaotic maps are used as secret keys in our scheme. The effectiveness of the proposed scheme is checked through a series of attacks. Experimental results demonstrate that the proposed scheme is not only secure but also achieves superior tamper detection and localization accuracy under different attacks. For instance in copy-and-paste attack and collage attack.

142 citations


Journal ArticleDOI
TL;DR: The commutative property of the proposed method allows to cipher a watermarked image without interfering with the embedded signal or to watermark an encrypted image still allowing a perfect deciphering.
Abstract: In this paper a commutative watermarking and ciphering scheme for digital images is presented. The commutative property of the proposed method allows to cipher a watermarked image without interfering with the embedded signal or to watermark an encrypted image still allowing a perfect deciphering. Both operations are performed on a parametric transform domain: the Tree Structured Haar transform. The key dependence of the adopted transform domain increases the security of the overall system. In fact, without the knowledge of the generating key it is not possible to extract any useful information from the ciphered-watermarked image. Experimental results show the effectiveness of the proposed scheme.

136 citations


Journal ArticleDOI
TL;DR: It is shown that the proposed scheme outperforms previous techniques in general and the smaller the tampered area, the more available watermark data will result in a better quality of recovered content.
Abstract: This paper proposes a novel watermarking scheme with flexible self-recovery quality. The embedded watermark data for content recovery are calculated from the original discrete cosine transform (DCT) coefficients of host image and do not contain any additional redundancy. When a part of a watermarked image is tampered, the watermark data in the area without any modification still can be extracted. If the amount of extracted data is large, we can reconstruct the original coefficients in the tampered area according to the constraints given by the extracted data. Otherwise, we may employ a compressive sensing technique to retrieve the coefficients by exploiting the sparseness in the DCT domain. This way, all the extracted watermark data contribute to the content recovery. The smaller the tampered area, the more available watermark data will result in a better quality of recovered content. It is also shown that the proposed scheme outperforms previous techniques in general.

135 citations


Journal ArticleDOI
TL;DR: This paper proposes a new watermarking approach which allows watermark detection and extraction under affine transformation attacks and stands on a set of affine invariants derived from Legendre moments.
Abstract: Geometric distortions are generally simple and effective attacks for many watermarking methods. They can make detection and extraction of the embedded watermark difficult or even impossible by destroying the synchronization between the watermark reader and the embedded watermark. In this paper, we propose a new watermarking approach which allows watermark detection and extraction under affine transformation attacks. The novelty of our approach stands on a set of affine invariants we derived from Legendre moments. Watermark embedding and detection are directly performed on this set of invariants. We also show how these moments can be exploited for estimating the geometric distortion parameters in order to permit watermark extraction. Experimental results show that the proposed watermarking scheme is robust to a wide range of attacks: geometric distortion, filtering, compression, and additive noise.

126 citations


Journal ArticleDOI
TL;DR: Experimental results show that the proposed GDWM outperforms other watermarking methods and is robust to a wide range of attacks, e.g., Gaussian filtering, amplitude scaling, median filtering, sharpening, JPEG compression, Gaussian noise, salt & pepper noise, and scaling.
Abstract: We propose a robust quantization-based image watermarking scheme, called the gradient direction watermarking (GDWM), based on the uniform quantization of the direction of gradient vectors. In GDWM, the watermark bits are embedded by quantizing the angles of significant gradient vectors at multiple wavelet scales. The proposed scheme has the following advantages: 1) increased invisibility of the embedded watermark because the watermark is embedded in significant gradient vectors, 2) robustness to amplitude scaling attacks because the watermark is embedded in the angles of the gradient vectors, and 3) increased watermarking capacity as the scheme uses multiple-scale embedding. The gradient vector at a pixel is expressed in terms of the discrete wavelet transform (DWT) coefficients. To quantize the gradient direction, the DWT coefficients are modified based on the derived relationship between the changes in the coefficients and the change in the gradient direction. Experimental results show that the proposed GDWM outperforms other watermarking methods and is robust to a wide range of attacks, e.g., Gaussian filtering, amplitude scaling, median filtering, sharpening, JPEG compression, Gaussian noise, salt & pepper noise, and scaling.

123 citations


Journal ArticleDOI
TL;DR: A watermarking method, which minimizes the impact of the watermark implementation on the overall quality of an image, is developed using a peak signal-to-noise ratio to evaluate quality degradation.
Abstract: In this paper, we evaluate the degradation of an image due to the implementation of a watermark in the frequency domain of the image. As a result, a watermarking method, which minimizes the impact of the watermark implementation on the overall quality of an image, is developed. The watermark is embedded in magnitudes of the Fourier transform. A peak signal-to-noise ratio is used to evaluate quality degradation. The obtained results were used to develop a watermarking strategy that chooses the optimal radius of the implementation to minimize quality degradation. The robustness of the proposed method was evaluated on the dataset of 1000 images. Detection rates and receiver operating characteristic performance showed considerable robustness against the print-scan process, print-cam process, amplitude modulated, halftoning, and attacks from the StirMark benchmark software.

115 citations


01 Jan 2011
TL;DR: A new optimal watermarking scheme based on lifting wavelet transform (LWT) and singular value decomposition (SVD) using multi-objective ant colony optimization (MOACO) is presented.
Abstract: In this paper, a new optimal watermarking scheme based on lifting wavelet transform (LWT) and singular value decomposition (SVD) using multi-objective ant colony optimization (MOACO) is presented. The singular values of the binary water- mark are embedded in a detail subband of host image. To achieve the highest possible robustness without losing watermark transparency, multiple scaling factors (MSF) are used instead of a single scaling factor (SSF). Determining the optimal values of the mul- tiple scaling factors (MSF) is a dicult problem. However, to determine these values, a multi-objective ant colony-based optimization method is used. Experimental results show much improved performances in terms of transparency and robustness for the proposed method compared to other watermarking schemes. Furthermore, the proposed scheme does not suer from the problem of high probability of false positive detections of the watermarks.

Journal ArticleDOI
TL;DR: A new audio watermarking algorithm based on singular value decomposition and dither-modulation quantization is presented that is quite robust against attacks including additive white Gaussian noise, MP3 compression, resampling, low-pass filtering, requantization, cropping, echo addition and denoising.
Abstract: Quantization index modulation is one of the best methods for performing blind watermarking, due to its simplicity and good rate-distortion-robustness trade-offs. In this paper, a new audio watermarking algorithm based on singular value decomposition and dither-modulation quantization is presented. The watermark is embedded using dither-modulation quantization of the singular values of the blocks of the host audio signal. The watermark can be blindly extracted without the knowledge of the original audio signal. Subjective and objective tests confirm high imperceptibility achieved by the proposed scheme. Moreover, the scheme is quite robust against attacks including additive white Gaussian noise, MP3 compression, resampling, low-pass filtering, requantization, cropping, echo addition and denoising. The watermark data payload of the algorithm is 196 bps. Performance analysis of the proposed scheme shows low error probability rates.

Journal ArticleDOI
TL;DR: Both the theoretical analysis and experimental results show that the proposed audio watermarking scheme is not only resilient against common signal processing operations, but also has conquered the challenging audio geometric distortion and achieves the best robustness against simultaneous geometric distortions.
Abstract: The development of a geometric invariant audio watermarking scheme without degrading acoustical quality is challenging work. This paper proposes a multi-bit spread-spectrum audio watermarking scheme based on a geometric invariant log coordinate mapping (LCM) feature. The LCM feature is very robust to audio geometric distortions. The watermark is embedded in the LCM feature, but it is actually embedded in the Fourier coefficients which are mapped to the feature via LCM, so the embedding is actually performed in the DFT domain without interpolation, thus eliminating completely the severe distortion resulted from the non-uniform interpolation mapping. The watermarked audio achieves high auditory quality in both objective and subjective quality assessments. A mixed correlation between the LCM feature and a key-generated PN tracking sequence is proposed to align the log-coordinate mapping, thus synchronizing the watermark efficiently with only one FFT and one IFFT. Both the theoretical analysis and experimental results show that the proposed audio watermarking scheme is not only resilient against common signal processing operations, including low-pass filtering, MP3 recompression, echo addition, volume change, normalization, test functions in the Stirmark benchmark, and DA/AD conversion, but also has conquered the challenging audio geometric distortion and achieves the best robustness against simultaneous geometric distortions, such as pitch invariant time-scale modification (TSM) by ±20%, tempo invariant pitch shifting by 20%, resample TSM with scaling factors between 75% and 140%, and random cropping by 95%. This is mainly contributed by the proposed geometric invariant LCM feature. To our best knowledge, audio watermarking based on LCM has not been reported before.

Proceedings Article
01 Jan 2011
TL;DR: SWIRL is the first watermark that is practical to use for large-scale traffic analysis and is robust to packet losses and network jitter, yet it introduces only small delays that are invisible to both benign users and determined adversaries.
Abstract: Flow watermarks are active traffic analysis techniques that help establish a causal connection between two network flows by content-independent manipulations, e.g., altering packet timings. Watermarks provide a much more scalable approach for flow correlation than passive traffic analysis. Previous designs of scalable watermarks, however, were subject to multi-flow attacks. They also introduced delays too large to be used in most environments. We design SWIRL, a Scalable Watermark that is Invisible and Resilient to packet Losses. SWIRL is the first watermark that is practical to use for large-scale traffic analysis. SWIRL uses a flow-dependent approach to resist multi-flow attacks, marking each flow with a different pattern. SWIRL is robust to packet losses and network jitter, yet it introduces only small delays that are invisible to both benign users and determined adversaries. We analyze the performance of SWIRL both analytically and on the PlanetLab testbed, demonstrating very low error rates. We consider applications of SWIRL to stepping stone detection and linking anonymous communication. We also propose a novel application of watermarks to defend against congestion attacks on Tor.

Journal ArticleDOI
TL;DR: The experimental results show that the proposed semi-fragile watermarking scheme outperforms four peer schemes and is capable of identifying intentional tampering and incidental modification, and localizing tampered regions.

Journal ArticleDOI
TL;DR: Experimental results on several test sequences demonstrate that the proposed information hiding algorithm for H.264/AVC video stream can realize blind extraction with real-time performance.
Abstract: An information hiding algorithm based on intra-prediction modes and matrix coding is proposed for H.264/AVC video stream. It utilizes the block types and modes of intra-coded blocks to embed watermark. intra- 4 × 4 coded blocks (I4-blocks) are divided into groups and two watermark bits are mapped to every three I4-blocks by matrix coding to map between watermark bit and intra-prediction modes. Since only the mode of an I4-block is changed for every two watermark bits, it can guarantee a high PSNR and slight bitrate increase after watermark embedding. Moreover, embedding position template is utilized to select candidate I4-blocks for watermark embedding, which further enhances the security of watermark information. Experimental results on several test sequences demonstrate that the proposed approach can realize blind extraction with real-time performance.

Journal ArticleDOI
TL;DR: This paper proposes a correlation-and-bit-aware concept for data hiding by exploiting the side information at the encoder side, and presents two improved data hiding approaches based on the popular additive spread spectrum embedding idea.
Abstract: This paper proposes a correlation-and-bit-aware concept for data hiding by exploiting the side information at the encoder side, and we present two improved data hiding approaches based on the popular additive spread spectrum embedding idea. We first propose the correlation-aware spread spectrum (CASS) embedding scheme, which is shown to provide better watermark decoding performance than the traditional additive spread spectrum (SS) scheme. Further, we propose the correlation-aware improved spread spectrum (CAISS) embedding scheme by incorporating SS, improved spread spectrum (ISS), and the proposed correlation-and-bit-aware concept. Compared with the traditional additive SS, the proposed CASS and CAISS maintain the simplicity of the decoder. Our analysis shows that, by efficiently incorporating the side information, CASS and CAISS could significantly reduce the host effect in data hiding and improve the watermark decoding performance remarkably. To demonstrate the improved decoding performance and the robustness by employing the correlation-and-bit-aware concept, the theoretical bit-error performances of the proposed data hiding schemes in the absence and presence of additional noise are analyzed. Simulation results show the superiority of the proposed data hiding schemes over traditional SS schemes.

01 Jan 2011
TL;DR: A DCT based watermarking scheme is proposed which provides higher resistance to image processing attacks such as JPEG compression, noise, rotation, translation etc .
Abstract: Since all the multimedia products are released via internet so it’s an urgent need today to protect the data from malicious attacks. This lead to the research in the area of Digital watermarking which intends to protect the copyright information of the intellectuals. In this paper a DCT based watermarking scheme is proposed which provides higher resistance to image processing attacks such as JPEG compression, noise, rotation, translation etc .In this approach, the watermark is embedded in the mid frequency band of the DCT blocks carrying low frequency components and the high frequency sub band components remain unused. Watermark is inserted by adjusting the DCT coefficients of the image and by using the private key. Watermark can then be extracted using the same private key without resorting to the original image. Performance analysis shows that the watermark is robust.

Journal ArticleDOI
31 Mar 2011
TL;DR: A new method for non-blind image watermarking that is robust against affine transformation and ordinary image manipulation is presented and higher performance of the proposed method in comparison with the DWT-SVD method is shown.
Abstract: In this paper, a new method for non-blind image watermarking that is robust against affine transformation and ordinary image manipulation is presented. The suggested method presents a watermarking scheme based on redundant discrete wavelet transform and Singular Value Decomposition. After applying RDWT to both cover and watermark images, we apply SVD to the LL subbands of them. We then modify singular values of the cover image using singular values of the visual watermark. The advantage of the proposed technique is its robustness against most common attacks. Analysis and experimental results show higher performance of the proposed method in comparison with the DWT-SVD method.

Journal ArticleDOI
TL;DR: This paper proposes an intelligent watermarking by invoking particle swarm optimization (PSO) technique in wavelet domain to overcome the revealed insecurity issue, furthermore resolve the conflict between imperceptibility and robustness of watermarked.
Abstract: Meerwald, Koidl, and Uhl (2009) pointed out that the method proposed in Lin et al. (2008) exists potential insecurity. This paper proposes an intelligent watermarking by invoking particle swarm optimization (PSO) technique in wavelet domain to overcome the revealed insecurity issue, furthermore resolve the conflict between imperceptibility and robustness of watermarking. In the proposed method, PSO is fused with the method proposed in Lin et al. (2008) (denoted SDWCQ) to avoid potentially insecurity in Lin et al. (2008). That is, the method of using the fixed block size in one subband and the permutation is unable to disguise which coefficients make up a block. The attacker can utilize the insecure property and analyze the significant difference between bipolar watermarks in Lin et al. (2008) to detect the embedded blocks, furthermore modify the significant difference, and result in unable to extract the watermark. In this paper, coefficients are randomly selected from different subbands to make up a block to promote the disguise. Performance analysis shows that the proposed algorithm obviously outperforms SDWCQ which does not use PSO.

Journal ArticleDOI
TL;DR: In this paper, a new FSM watermarking scheme is proposed by making the authorship information a non-redundant property of the FSM to overcome the vulnerability to state removal attack and minimize the design overhead.
Abstract: Finite state machines (FSMs) are the backbone of sequential circuit design. In this paper, a new FSM watermarking scheme is proposed by making the authorship information a non-redundant property of the FSM. To overcome the vulnerability to state removal attack and minimize the design overhead, the watermark bits are seamlessly interwoven into the outputs of the existing and free transitions of state transition graph (STG). Unlike other transition-based STG watermarking, pseudo input variables have been reduced and made functionally indiscernible by the notion of reserved free literal. The assignment of reserved literals is exploited to minimize the overhead of watermarking and make the watermarked FSM fallible upon removal of any pseudo input variable. A direct and convenient detection scheme is also proposed to allow the watermark on the FSM to be publicly detectable. Experimental results on the watermarked circuits from the ISCAS'89 and IWLS'93 benchmark sets show lower or acceptably low overheads with higher tamper resilience and stronger authorship proof in comparison with related watermarking schemes for sequential functions.

Journal ArticleDOI
TL;DR: The proposed contourlet-based watermarking algorithm uses an automatically selection for ROI and embeds the watermark in the singular values of contourlets subbands that makes the algorithm more efficient, and robust against noise attacks than other transform domains.
Abstract: Nowadays, medical imaging equipments produce digital form of medical images. In a modern health care environment, new systems such as PACS (picture archiving and communication systems), use the digital form of medical image too. The digital form of medical images has lots of advantages over its analog form such as ease in storage and transmission. Medical images in digital form must be stored in a secured environment to preserve patient privacy. It is also important to detect modifications on the image. These objectives are obtained by watermarking in medical image. In this paper, we present a dual and oblivious (blind) watermarking scheme in the contourlet domain. Because of importance of ROI (region of interest) in interpretation by medical doctors rather than RONI (region of non-interest), we propose an adaptive dual watermarking scheme with different embedding strength in ROI and RONI. We embed watermark bits in singular value vectors of the embedded blocks within lowpass subband in contourlet domain. The values of PSNR (peak signal-to-noise ratio) and SSIM (structural similarity measure) index of ROI for proposed DICOM (digital imaging and communications in medicine) images in this paper are respectively larger than 64 and 0.997. These values confirm that our algorithm has good transparency. Because of different embedding strength, BER (bit error rate) values of signature watermark are less than BER values of caption watermark. Our results show that watermarked images in contourlet domain have greater robustness against attacks than wavelet domain. In addition, the qualitative analysis of our method shows it has good invisibility. The proposed contourlet-based watermarking algorithm in this paper uses an automatically selection for ROI and embeds the watermark in the singular values of contourlet subbands that makes the algorithm more efficient, and robust against noise attacks than other transform domains. The embedded watermark bits can be extracted without the original image, the proposed method has high PSNR and SSIM, and the watermarked image has high transparency and can still conform to the DICOM format.

Patent
02 Nov 2011
TL;DR: A variety of methods and systems involving sensor-equipped portable devices, such as smartphones and tablet computers, are described in this article, where the salient point data enables the device to interact with the object in a spatially-dependent manner.
Abstract: A variety of methods and systems involving sensor-equipped portable devices, such as smartphones and tablet computers, are described. One particular embodiment decodes a digital watermark from imagery captured by the device and, by reference to watermark payload data, obtains salient point data corresponding to an object depicted in the imagery. Other embodiments obtain salient point data for an object through use of other technologies (e.g., NFC chips). The salient point data enables the device to interact with the object in a spatially-dependent manner. Many other features and arrangements are also detailed.

Journal ArticleDOI
TL;DR: A robust and blind watermarking algorithm for three-dimensional (3D) meshes that embeds the watermark through a modified scalar Costa quantization of the zero-order volume moments of some selected candidate patches.

Journal ArticleDOI
TL;DR: Experimental results show that the proposed scheme can discriminate the malicious tampering from the mild signal processing and the tampered location can also be approximately determined according to the glide window and the predefined threshold.
Abstract: As the H.264/AVC-based video products become more and more popular, issues of copyright protection and authentication that are appropriate for this standard will be very important. In this paper, a content-based authentication watermarking scheme for H.264/AVC video is proposed. Considering the new feature of H.264/AVC, the content-based authentication code for spatial tampering is firstly generated using the reliable features extracted from video frame blocks. The authentication code, which can detect malicious manipulations but allow recompression, is embedded into the DCT coefficients in diagonal positions using a novel modulation method. Spatial tampering can be located by comparing the extracted and the original feature-based watermarks. In addition, combining ECC and interleaving coding, the frame index of each video frame is used as watermark information and embedded in the residual coefficients. Temporal tampering can be detected by the mismatch between the extracted and the observed frame index. Experimental results show that the proposed scheme can discriminate the malicious tampering from the mild signal processing. The tampered location can also be approximately determined according to the glide window and the predefined threshold.

Journal ArticleDOI
TL;DR: A novel semi-fragile spatial watermarking method based on LBP operators by using the local pixel contrast for the embedding and extraction of watermarks is presented and a general framework for multi-level imageWatermarking is proposed.

01 Jan 2011
TL;DR: A hybrid digital video watermarking scheme based on Discrete Wavelet Transform (DWT) and Principal Component Analysis (PCA) and helps in reducing correlation among the wavelet coefficients obtained from wavelet decomposition of each video frame thereby dispersing the watermark bits into the uncorrelated coefficients.
Abstract: Due to the extensive use of digital media applications, multimedia security and copyright protection has gained tremendous importance. Digital Watermarking is a technology used for the copyright protection of digital applications. In this paper, a comprehensive approach for watermarking digital video is introduced. We propose a hybrid digital video watermarking scheme based on Discrete Wavelet Transform (DWT) and Principal Component Analysis (PCA). PCA helps in reducing correlation among the wavelet coefficients obtained from wavelet decomposition of each video frame thereby dispersing the watermark bits into the uncorrelated coefficients. The video frames are first decomposed using DWT and the binary watermark is embedded in the principal components of the low frequency wavelet coefficients. The imperceptible high bit rate watermark embedded is robust against various attacks that can be carried out on the watermarked video, such as filtering, contrast adjustment, noise addition and geometric attacks.

Journal ArticleDOI
TL;DR: This work proposes a public digital watermarking technique for video copyright protection in the discrete wavelet transform domain, which achieves a good perceptual quality and high resistance to a large spectrum of attacks.
Abstract: The development of the information technology and computer networks facilitates easy duplication, manipulation, and distribution of digital data. Digital watermarking is one of the proposed solutions for effectively safeguarding the rightful ownership of digital images and video. We propose a public digital watermarking technique for video copyright protection in the discrete wavelet transform domain. The scheme uses binary images as watermarks. These are embedded in the detail wavelet coefficients of the middle wavelet subbands. The method is a combination of spread spectrum and quantization-based watermarking. Every bit of the watermark is spread over a number of wavelet coefficients with the use of a secret key by means of quantization. The selected wavelet detail coefficients from different subbands are quantized using an optimal quantization model, based on the characteristics of the human visual system (HVS). Our HVS-based scheme is compared to a non-HVS approach. The resilience of the watermarking algorithm is tested against a series of different spatial, temporal, and compression attacks. To improve the robustness of the algorithm, we use error correction codes and embed the watermark with spatial and temporal redundancy. The proposed method achieves a good perceptual quality and high resistance to a large spectrum of attacks.

Journal ArticleDOI
TL;DR: Experimental results show that the proposed color image watermarking is not only invisible and robust against common image processing operations such as filtering, noise adding, and JPEG compression etc., but also robust against the geometrical distortions.
Abstract: Geometric distortion is known as one of the most difficult attacks to resist, for it can desynchronize the location of the watermark and hence causes incorrect watermark detection. It is a challenging work to design a robust color image watermarking scheme against geometric distortions. Based on the support vector regression (SVR) and nonsubsampled contourlet transform (NSCT), we propose a new color image watermarking algorithm with good visual quality and reasonable resistance toward geometric distortions in this paper. Firstly, the geometrically invariant space is constructed by using color image normalization, and a significant region is obtained from the normalized color image by utilizing the invariant centroid theory. Then, the NSCT is performed on the green channel of the significant region. Finally, the digital watermark is embedded into host color image by modifying the low frequency NSCT coefficients, in which the HVS masking is used to control the watermark embedding strength. In watermark detection, according to the high correlation among different channels of the color image, the digital watermark can be recovered by using SVR technique. Experimental results show that the proposed color image watermarking is not only invisible and robust against common image processing operations such as filtering, noise adding, and JPEG compression etc., but also robust against the geometrical distortions.

Patent
15 Sep 2011
TL;DR: In this article, a watermark extraction and content screening operation can be organized such that some or all of the operations can be conducted at different times by different devices, and the authenticity of various devices can be verified through exchange of certificates that can further enable such devices to ascertain capabilities of one another.
Abstract: Methods, devices, and computer program products facilitate the application of a content use policy based on watermarks that are embedded in a content. Watermark extraction and content screening operations, which can include the application of content usage enforcement actions, may be organized such that some or all of the operations can be conducted at different times by different devices. These operations can be conducted by one or more trusted devices that reside in a networked environment. The authenticity of various devices can be verified through the exchange of certificates that can further enable such devices to ascertain capabilities of one another. Based on the ascertained capabilities, an operational configuration for conducting watermark extraction and content screening can be determined.