Watermark Bits Research Articles

Adaptive stereo medical image watermarking using non-corresponding blocks.

Today with the advent of technology in different medical imaging fields, the use of stereoscopic images has increased. Furthermore, with the rapid growth in telemedicine for remote diagnosis, treatment, and surgery, there is a need for watermarking. This is for copyright protection and tracking of digital media. Also, the efficient use of bandwidth for transmission of such data is another concern. In this paper an adaptive watermarking scheme is proposed that considers human visual system in depth perception. Our proposed scheme modifies maximum singular values of wavelet coefficients of stereo pair for embedding watermark bits. Experimental results show high 3D visual quality of watermarked video frames. Moreover, comparison with a compatible state of the art method shows that the proposed method is highly robust against attacks such as AWGN, salt and pepper noise, and JPEG compression.

연속적 차분 확장 기반 가역 DNA 워터마킹

Of recent interests on high capacity DNA storage, DNA watermarking for DNA copyright protection, and DNA steganography for DNA secret communication are augmented, the reversible DNA watermarking is much needed both to embed the watermark without changing the functionality of organism and to perfectly recover the host DNA sequence. In this paper, we address two ways of DE based reversible DNA watermarking using noncoding DNA sequence. The reversible DNA watermarking should consider the string structure of a DNA sequence, the organism functionality, the perfect recovery, and the high embedding capacity. We convert the string sequence of four characters in noncoding region to the decimal coded values and embed the watermark bit into coded values by two ways; DE based multiple bits embedding (DE-MBE) using pairs of neighbor coded values and consecutive DE-MBE (C-DE-MBE). Two ways process the comparison searching to prevent the false start codon that produces false coding region. Experimental results verified that our ways have more high embedding capacity than conventional methods and produce no false start codon and recover perfectly the host sequence without the reference sequence. Especially C-DE-MBE can embed more high two times than DE-MBE.

Significant region based robust watermarking scheme in lifting wavelet transform domain

With the aim of designing a more robust digital watermarking scheme against various unintentional and intentional attacks, a significant region (SR) based image watermarking technique is proposed in the present paper using lifting wavelet transform (LWT). While the energy compaction property of LWT provides higher tolerance against image distortion as opposed to conventional wavelet transform, the proposed block selection procedure provides greater security over the existing watermarking approaches. Non-overlapping coefficient blocks from the lowpass subband are selected after applying three levels of LWT and using certain criterion based on minimum coefficient difference and a threshold value. To disguise the intruder completely, secret key based randomization of coefficients, blocks, and watermark bits is incorporated. Maximum coefficients difference of each selected block and the same threshold value are then used for deciding which block to choose for embedding the bit 0 or 1. Performance of the proposed method is analyzed and compared with some of the existing schemes that demonstrates that the proposed scheme not only outperforms other methods with respect to various attacks for most of the cases, but also maintains a satisfactory image quality.

A Secure Speech Content Authentication Algorithm Based on Discrete Fractional Fourier Transform

Watermark schemes content-based provide one way to solve the veracity and integrity of speech content. Some existed content-based schemes are vulnerable to feature-analysed substitution attack. Aiming to solve the problems, a secure speech content authentication algorithm is proposed, on the basic of the undeterminate angle of discrete fractional fourier transform. In the paper, the definition and calculation of discrete fractional fourier transform are given. And the watermark generation method based on discrete fractional fourier transform is analyzed. Frame number and watermark bits are embedded into hybrid domain of scrambled signals. Compared with the existed watermark schemes, the features for watermark generation and embedding are secret, which improves the security of watermark system. Theoretical analysis and experimental evaluation results show that the proposed algorithm is inaudible, robust to desynchronous attacks and has the excellent ability of tamper detection and tamper location.

Audio dual watermarking scheme for copyright protection and content authentication

We propose a new multipurpose audio watermarking scheme in which two watermarks are used. For intellectual property protection, audio clip is divided into frames and robust watermark is embedded. At the same time, the feature of each frame is extracted, and it is quantized as semi-fragile watermark. Then, the frame is cut into sections and the semi-fragile watermark bits are embedded into these sections. For content authentication, the semi-fragile watermark extracted from each frame is compared with the watermark generated from the same frame to judge whether the watermarked audio is tampered, and locate the tampered position. Experimental results show that our scheme is inaudibility. The two watermark schemes are all robust to common signal processing operations such as additive noise, resampling, re-quantization and low-pass filtering, and the semi-fragile watermark scheme can achieve tampered detection and location.

Digital watermark extraction using support vector machine with principal component analysis based feature reduction

This paper proposes a new approach for watermark extraction using support vector machine (SVM) with principal component analysis (PCA) based feature reduction. In this method, the original cover image is decomposed up to three level using lifting wavelet transform (LWT), and lowpass subband is selected for data hiding purpose. The lowpass subband is divided into small blocks, and a binary watermark is embedded into the original cover image by quantizing the two maximum coefficients of the block. In order to extract watermark bits with maximum correlation, SVM based binary classification approach is incorporated. The training and testing patterns are constructed by employing a reduced set of features along with block coefficients. Firstly, different features are obtained by evaluating the statistical parameters of each block coefficients, and then PCA is utilized to reduce this feature set. As far as security is concerned, randomization of coefficients, blocks, and watermark bits enhances the security of system. Furthermore, energy compaction property of LWT increases the robustness in comparison to conventional wavelet transform. A comparison of the proposed method with some of the recent techniques shows remarkable improvement in terms of robustness and security of the watermark.

English

In today’s growing world of digital technology, access to the multimedia content is very easy and for some sensitive applications such as medical imaging, military system, legal problems, it is very essential to not only reinstate the original media without any loss of information but also to increase content’s security. Reversible data hiding is an approach to extract the information embedded covertly as well as the host image. In this paper, we have proposed a novel hybrid invisible watermarking scheme based on DWT, DCT and SVD. In this scheme, we have provided double layer of security by utilizing the multi-resolution property of wavelet and strong features of DCT and SVD. In the proposed scheme, watermark is embedded into the singular values of all high frequency sub-bands obtained by wavelet decomposition of the original image and at the time of extraction, watermark bits are used along with singular vectors to obtain the original image. Our scheme provides high security as even after the extraction of watermark, without knowing the extraction algorithm, original image cannot be recovered in its entirety. The proposed scheme is tested on various test images and the obtained results show the effectiveness of the proposed scheme. Indexing terms/Keywords

Reversible watermarking based on two embedding Schemes

Two different embedding schemes are presented in this paper. One aims to increase rate-distortion performance at low embedding rates. It will increase performance at low embedding rates from the following three main aspects: 1) a local variance-controlled mechanism, 2) a better predictor and 3) a new embedding scheme which can decrease the number of the pixels to be modified on the basis of providing a certain embedding capacity. Since the first scheme is only to provide low embedding rate with high visual quality, another scheme is designed to achieve higher embedding rate with good visual quality. In the second scheme, the center pixel of a three-pixel set is the prediction of a pixel, and thus any modification to it is meaningless. Each three-pixel set contains two differences. Based on the fact that the center pixel can not be modified, the remaining two pixels must be modified so that both of difference are shifted by 1. For instance, if both of pixels can carry 1-bit watermark and to-be-embedded bits are both 1, then two pixels must be shifted left or right by 1. Since we can not shift two difference by modifying only the center pixel, the distortion is high. To decrease distortion, the possibility that two bits are both equal to 1 is discarded in this paper. Experimental results also demonstrate the proposed method is effective.

A Robust Watermarking Scheme Based on Least Significant Bit and Discrete Cosine Transform

In this paper, an image watermarking scheme is presented, in which Least Significant Bit and discrete cosine transform are used. The discrete cosine transform is performed on the original host image, and the secret watermark image is embedded into the coefficient of discrete cosine transform, which will replace the least significant bit. The embedded secret watermark bit will cause minimal distortion of the original host image, but we cannot find the difference of the original host image and the watermarked image. The experiment based on this algorithm demonstrates that the watermarking is robust to the common signal processing techniques, including noise attack, JPEG Compression attack and so on.

Anti-counterfeiting digital watermarking algorithm for printed QR barcode

Anti-counterfeiting watermarking technology provides a potential way to prevent quick response (QR) barcode from being copied or forged, and many relevant algorithms for digital QR barcode appeared recently. However, as for printed QR barcode, there is no actual research achievement published. This paper studies anti-counterfeiting techniques for printed QR barcode. The primary performance parameter, decoding rate of QR barcode as well as detection rate of digital watermark, is defined and discussed. A multi-channel robust watermarking scheme based on discrete wavelet transform (DWT) is proposed. In the watermarking scheme, the DWT domain is divided into non-overlapping rectangular areas as called watermarking channels. Channel watermark as well as anti-counterfeiting watermark is embedded into each watermarking channel. At the stage of anti-counterfeiting watermark extracting, the distortion rates of the watermarking channels are estimated by channel watermark. Based on the distortion rates, anti-counterfeiting watermark is computed by a well-designed linear estimation algorithm, whose validity is theoretically proved by analyzing anti-counterfeiting watermark bit error. The experimental results show that the detection rate of anti-counterfeiting watermark is greatly improved with the proposed scheme, and that we can correctly extract anti-counterfeiting watermark from printed QR image by choosing reasonable parameters.

Robust lossless digital watermarking using integer transform with Bit plane manipulation

In this paper, a robust lossless digital watermarking scheme based on a generalized integer transform in spatial domain is proposed. In the proposed method, data bits are hidden into the cover media by a reversible generalized integer transform with bit plane manipulation. With the reversible transform, data can be hidden in the cover media, and the stego media can be restored to its original form after extraction of the hidden data. In embedding procedure, adaptive bit plane manipulation is applied to increase robustness of the algorithm while keeps good visual quality. To further increase the robustness of the algorithm, we repeatedly embed watermark bits and use majority voting to decode the hidden information in extraction procedure. Furthermore, a threshold is introduced in the algorithm, which helps in choosing regions that would result lower variance for embedding, as regions with lower variance is more robust against JPEG compression. The proposed scheme is quite different from the existing robust lossless data hiding algorithms which are histogram-based. The performance of the proposed scheme is evaluated and compared with state-of-the-arts techniques respect to robustness, data payload capacity and peak signal-to-noise ratio (PSNR). In the experiments, the proposed method can embed more than 10000 bits into 512 by 512 grayscale and medical images, and has around 30 dB in PSNR. In case of small watermark with 100 bits, marked images can have PSNR above 60 dB and with 0.1 bpp in JPEG robustness in the best cases. Conclusively, the robustness of the proposed method is quite good, and the results of hiding capacity and imperceptibility are also satisfactory.

An Information Hiding Approach Based on Integer Transform Coefficient and Virtual Space Encoding for H.264/AVC

This paper gives an information hiding method for H.264/AVC compressed video stream based on integer transform coefficient and virtual space encoding. In this method, the integer transform coefficients which are selected as carriers are divided into multiple groups. And it only needs to change at most the value of one of the coefficients in each group to embed $$\hbox {Log}_{2}(2N+1)$$Log2(2N+1) binary bits when each group contains $$N$$N coefficients. Moreover, the required change is simple, which can be achieved by adding 1 or $$-$$-1 to the coefficient. Since only one coefficient's value is slightly changed for every $$\hbox {Log}_{2}(2N+1)$$Log2(2N+1) secret bits, this method does less harm to the original encoded video stream caused by the information embedding compared with that by current methods. Furthermore, this method only chooses the macroblock that has rich texture as the candidate carrier macroblock, and it employs the embedding position template to select the candidate $$4\times 4$$4×4 coded blocks (I4-blocks) from the carrier macroblock for watermark bits embedding. In this way, the counteracting steganalysis performance is significantly improved. Experimental results on several test sequences demonstrate that the proposed approach can realize blind extraction and the performance is superior to that of the other current state-of-the-art information hiding methods also based on modulating integer transform coefficients.

Information Hiding Method Using Best DCT and Wavelet Coefficients and Its Watermark Competition

In recent years, information hiding and its evaluation criteria have been developed by the IHC (Information Hiding and its Criteria) Committee of Japan. This committee was established in 2011 with the aim of establishing standard evaluation criteria for robust watermarks. In this study, we developed an information hiding method that satisfies the IHC evaluation criteria. The proposed method uses the difference of the frequency coefficients derived from a discrete cosine transform or a discrete wavelet transform. The algorithm employs a statistical analysis to find the best positions in the frequency domains for watermark insertion. In particular, we use the BCH (Bose-Chaudhuri-Hocquenghem) (511,31,109) code to error correct the watermark bits and the BCH (63,16,11) code as the sync signal to withstand JPEG (Joint Photographic Experts Group) compression and cropping attacks. Our experimental results showed that there were no errors in 10 HDTV-size areas after the second decompression. It should be noted that after the second compression, the file size should be less than 1 25 of the original size to satisfy the IHC evaluation criteria.

A good performance watermarking LDPC code used in high-speed optical fiber communication system

A watermarking LDPC code, which is a strategy designed to improve the performance of the traditional LDPC code, was introduced. By inserting some pre-defined watermarking bits into original LDPC code, we can obtain a more correct estimation about the noise level in the fiber channel. Then we use them to modify the probability distribution function (PDF) used in the initial process of belief propagation (BP) decoding algorithm. This algorithm was tested in a 128Gb/s PDM-DQPSK optical communication system and results showed that the watermarking LDPC code had a better tolerances to polarization mode dispersion (PMD) and nonlinearity than that of traditional LDPC code. Also, by losing about 2.4% of redundancy for watermarking bits, the decoding efficiency of the watermarking LDPC code is about twice of the traditional one.

A robust and efficient image watermarking scheme based on Lagrangian SVR and lifting wavelet transform

In this paper, an efficient image watermarking scheme based on Lagrangian support vector regression (LSVR) and lifting wavelet transform (LWT) is proposed to balance the trade-off between imperceptibility and robustness. LWT is faster and efficient implementation of traditional wavelet transform and LSVR has faster learning speed and high generalization capability compared to classical support vector regression. Combination of LWT and LSVR based image watermarking not only show imperceptibility and robustness but also reduces the time complexity. First the image is decomposed into four subbands using one level LWT and low frequency subband (approximate image) is partitioned into non overlapping blocks. Selected blocks based on correlation of wavelet coefficients are used to embed the binary watermark logo. For each selected block, significant wavelet coefficient is used as target to LSVR and its neighboring coefficients (feature vector) act as input to LSVR. The security of the watermark is achieved by applying Arnold transformation to original watermark. The scrambled watermark bit is embedded by comparing the output (predicted value) of LSVR of each selected block and the actual target value. The good learning capability and high generalization property of LSVR against noisy datasets provides the successful extraction of watermark against several image processing attacks: median filtering, average filtering, addition of Gaussian noise, salt and pepper noise, contrast enhancement, blurring, scaling, cropping and rotation. Experimental results show that the proposed scheme gives significant improvement in imperceptibility and robustness compared to the state-of-art techniques.

Experimental Study of Improved Watermarking Scheme on Relational Databases

The main objective of watermarking is to protect a digital content from unauthorized redistribution and copying by enabling ownership provability over the content. The goal of digital watermarking is to insert a robust and imperceptible watermark into the digital content such that the mark does not destroy the value of the content, and the mark is hard to be removed by attackers without destroying the utility of content. The measurement of the value of the content is closely related to the data type and its intended use. We have proposed a new marking scheme called as improved watermarking. Watermarking scheme first generates the bit string of fixed length. The mark bit is computed with the help of watermark bit and mask bit, which is used to mark the certain bit location of the attribute value. General Terms Relational Database Security, Improved Watermarking on Relational Database

An image watermarking scheme in wavelet domain with optimized compensation of singular value decomposition via artificial bee colony

Digital image watermarking is the process of authenticating a digital image by embedding a watermark into it and thereby protecting the image from copyright infringement. This paper proposes a novel robust image watermarking scheme developed in the wavelet domain based on the singular value decomposition (SVD) and artificial bee colony (ABC) algorithm. The host image is transformed into an invariant wavelet domain by applying redistributed invariant wavelet transform, subsequently the low frequency sub-band of wavelet transformed image is segmented into non-overlapping blocks. The most suitable embedding blocks are selected using the human visual system for the watermark embedding. The watermark bits are embedded into the target blocks by modifying the first column coefficients of the left singular vector matrix of SVD decomposition with the help of a threshold and the visible distortion caused by the embedding is compensated by modifying the coefficients of the right singular vector matrix employing compensation parameters. Furthermore, ABC is employed to obtain the optimized threshold and compensation parameters. Experimental results, compared with the related existing schemes, demonstrated that the proposed scheme not only possesses the strong robustness against image manipulation attacks, but also, is comparable to other schemes in term of visual quality.

Performance analysis of LDPC code based on Watermark scheme in high-speed optical communication system

We study the decoding performance of low-density parity-check (LDPC) code based on Watermark scheme under different percentages of water-mark bits over 100 Gb/s differential quadrature phase shift keying (DQPSK) high-speed optical communication system. We also find the optimum percentage of water-mark bits according to the performance comparison. Simulation result shows an improvement of 0.5 dB net code gain by using the optimum Watermark scheme at a post-forward error correction bit error rate (BER) of 10-9, comparing with the traditional log-likelihood ratios belief propagation decoding algorithm. Also, for the same BER, there is a decrease in the number of iterations used in LDPC decoding.

A Robust Watermarking Scheme Based on Maximum Wavelet Coefficient Modification and Optimal Threshold Technique

Digital watermarking has received extensive attention as a new method for copyright protection. This paper proposes a robust watermarking algorithm based on maximum wavelet coefficient modification and optimal threshold technique. The medium wavelet coefficients are randomly permutated according to a secret key and divided into subgroups. We modify the maximum wavelet in each subgroup according to the embedded watermark bits, which can effectively resist attacks. During the extraction process, an optimal threshold value calculated by iterative computation is used to extract the watermark from the watermarked image under different attacks, without using the original image or watermark. Numerous experiments are conducted to evaluate the watermarking performance. Experimental results demonstrate the superiority of our scheme on robustness against content-preserving operations and incidental distortions such as JPEG compression, Gaussian noise, median filter, resizing, cropping, and sharpening.

Digital Image Watermarking Algorithms Based on Dual Transform Domain and Self-Recovery

Abstract In view of dual watermarking algorithm for dual two value image watermarking, the watermark information there is a gray image watermarking in the expression is obviously insufficient. The proposed embedded in the carrier image on the dual watermark includes a two watermark image and a gray image watermarking algorithm, the persuasive power while maintaining the original two values of the watermark robustness at the same time, improve the watermark information. In order to balance the robustness and invisibility of watermarking algorithm, this paper analyzes the embedding position and strategy of transform domain algorithms, the DC coefficient in the carrier image is divided into blocks of DCT spectrum and spectrum on the combination of DWT coefficient method and the advantage of embedded dual watermarking, and use the NEC characteristic of the algorithm is improved adaptive based on the embedded mode. The gray image watermark bit plane decomposition compression high four bit plane information as watermarking, in reducing the original watermark loading and enhance the overall strength of self recovery system. This paper from the working principle, classification of digital watermarking, attack types, performance index, evaluation method and uses six aspects were introduced to the digital watermarking technology. Simulation study of a digital image watermarking algorithm based on DCT transform and Arnold transform, the algorithm’s imperceptibility, robustness and security are analyzed, the algorithm for embedding process.