An image copyright protection scheme by encrypting secret data with the host image

In this paper, a zero-watermarking based copyright protection scheme is proposed. The secret watermark image is not embedded in the host image rather it is encrypted with the host image. The proposed scheme is making use of discrete cosine transform and singular value decomposition to extract robust features of the host image. Further the selected robust features are used to encrypt the secret image. The secret image is encrypted with the host image by generating two shares namely master share and ownership share. The master share is generated by differential classification of features extracted. The ownership share is generated with the help of master share and the secret image. The two shares separately don’t give any clue of the secret image but when stacked together the encrypted secret image is revealed. Experimental study is conducted to evaluate the robustness of the algorithm against various signal processing and geometrical attacks.     

An efficient lossless robust watermarking scheme by integrating redistributed invariant wavelet and fractional Fourier transforms

An ensemble lossless watermarking scheme is proposed in the present study by integrating different concepts like redistributed invariant wavelet transform, discrete fractional Fourier transform, singular value decomposition (SVD) and visual cryptography within the framework of a single algorithm. The invariant wavelet transform helps to obtain the transform domain, which is invariant to flipping and rotation of image, this is followed by discrete fractional Fourier transform to obtain the translation invariant domain. Finally, embedding positions are selected based on a key and reliable features are extracted by performing SVD on a window centered at these positions. Based on these reliable features a binary map is generated through which a master share is created. The corresponding ownership share is produced from the master share and the watermark. In verification process the same operations of the embedding process are applied to the test image to obtain the master share and the watermark is recovered by stacking it over the ownership share. There are two main features of the proposed scheme (1) The quality of the image to be watermarked do not degrade during the process and (2) the extracted watermark can still be identified even from a seriously distorted image. These findings are also demonstrated with the help of a comparative study with several related schemes.     

A robust semi-blind watermarking for color images based on multiple decompositions

In this paper, a robust semi-blind watermarking scheme for color images, based on multiple decompositions is proposed to preserve the copyrights of the owner. Using multiple decompositions, the gray watermark is embedded into a host color image. Prior to that, to enhance security the gray watermark is encrypted with Arnold transform and SVD by generating secret keys. The luminance component of the given host image is subjected to discrete wavelet transform(DWT), contourlet transform(CT), Schur decomposition and singular value decomposition(SVD) in sequence and finally the watermark is embedded. In the semi-blind extraction process, the watermark is extracted without the help of the original host image. Experimental results show that the proposed watermarking scheme has better visual imperceptibility and high robustness against image & signal processing attacks compared to other methods.     

一种改进的DWT-SVD域参考水印方案

针对一类SVD域图像水印方案存在过高虚警概率的问题,提出了一种改进的混合DWT和SVD的图像参考水印算法。算法先对载体图像进行[n]层的离散小波变换,然后随机选取第[n]层的部分或全部子带形成参考子带,并对参考子带进行SVD分解;将Arnold置乱处理后的水印嵌入到SVD分解后的奇异值矩阵中。实验表明,提出的算法具有较好的透明性和安全性;与其他方案相比,解决了虚警概率问题,且对于大部分的攻击,具有更好的鲁棒性能。     

一种NMF和SVD相结合的鲁棒水印算法

提出了一种非负矩阵变换(NM})和奇异值分解(SVD)相结合的数字水印算法。该算法对宿主图像进行离散小波变换,然后选取低频部分进行非负矩阵变换和奇异值分解,最后在奇异值中嵌入Arnold置乱后的水印。实验表明,该算法在获得良好的视觉效果的同时,又具有很好的鲁棒性,对加噪、滤波、剪切等图像攻击有很好的抵杭能力。     

Robust copyright protection scheme for digital images using overlapping DCT and SVD

In this paper, a robust lossless copyright protection scheme, based on overlapping discrete cosine transform (DCT) and singular value decomposition (SVD), is presented. The original host image is separated into overlapping blocks, to which the DCT is applied. Direct current (DC) coefficients are extracted from the transformed blocks to form a DC-map. A series of random positions are selected on the map and SVD is performed to construct an ownership share which is used for copyright verification. Simulation results are carried out, demonstrating the robustness of the proposed scheme against different image-manipulation attacks.     

Rightful ownership through image adaptive DWT-SVD watermarking algorithm and perceptual tweaking

In this paper, a tailored blended image adaptive watermarking scheme has been presented, which is based on DWT and SVD. Through this paper an attempt has been made to solve the problem of false positive while maintaining the robustness and imperceptibility with the help of principal component and perceptual tuning of the image. Perceptual tuning is a non-blind technique and based on the objective quality of image. The embedding strength is made dependent on watermark features as well as of host in wavelet domain by using tuning parameter which is user specific. The idea of embedding the principal component of intermediate frequency sub-bands of watermark image into singular values of perceptually tuned intermediate frequency sub-bands of host image have been exploited. The proposed algorithm is providing the adaptive behavior towards the image content for perceptual transparency and at the same time avoiding the possibility of false watermark extraction well supported by a private key, which is necessary at the time of extraction. Thus the proposed watermarking algorithm is a kind of non-blind, image adaptive and suitable for rightful ownership. Various comparative results make the algorithm superior in terms of intentional and non-intentional attacks. Also the algorithm is strong against the print and scan attack.     

一种基于DWT域的数字图像零水印算法

提出了一种新的基于DWT和SVD变换技术的数字图像零水印算法。该方案利用载体图像变换后的特征信息与水印信息构造出版权信息,最后经加密再注册到IPR中;而检测水印时,需要版权信息与载体图像的特征信息;此外,算法还应用了图像置乱与混沌加密的方法,提高了鲁棒性和安全性。实验证明,此水印方案不改变载体图像的任何数据,而对常见的图像处理及几何变换攻击却有很强的鲁棒性,有效地解决了水印的鲁棒性与不可感知性之间的矛盾。     

基于感兴趣区域的图像水印嵌入算法研究

鉴于现有绝大多数图像水印方案将载体图像看作整个场景,并未考虑载体图像自身的结构特征及人们感兴趣的视觉目标区域,本文提出了一种基于感兴趣区(ROI)的小波域图像水印嵌入算法.该算法首先结合人眼视觉感知特性,在小波变换域内利用k-均值聚类提取出感兴趣区域;然后对感兴趣区域进行小波变换,并结合图像局部相关性对小波系数进行自适应的量化调制,将水印信息嵌入到感兴趣区域的低频子带内.仿真实验表明,所提出的水印嵌入算法不仅具有较好的透明性,而且对JPEG压缩、叠加噪声、锐化等常规图像处理操作具有较好的鲁棒性.特别地,该算法能够有效抵御恶意剪切、目标移动、替换背景等攻击,而且可以实现盲检测.     

A robust DWT-based copyright verification scheme with Fuzzy ART

Protecting the intellectual property rights (IPR) of digital media is important because the illegal reproduction and modification of digital media has become increasingly serious. A robust DWT-based copyright verification scheme with Fuzzy ART that does not require the original image for ownership verification is proposed in this paper. The proposed scheme, which combines DWT, Fuzzy ART, and the quantization process, converts an image into a short robust table with the embedded ownership information. Unlike general classification, such as k-mean and fuzzy c-means, the number of clusters can be adaptively decided by the vigilance parameter of Fuzzy ART. Experimental results demonstrate that the proposed scheme is robust against common image processing, geometric distortions, and intentional attacks. The original image is not required to extract the embedded ownership image.     

DWT-SVD and DCT based robust and blind watermarking scheme for copyright protection

In this article, a new DWT-SVD and DCT with Arnold Cat Map encryption based robust and blind watermarking scheme is proposed for copyright protection. The proposed scheme solves the most frequently occurring watermarking security problems in Singular Value Decomposition (SVD) based schemes which are unauthorized reading and false-positive detection. This scheme also optimizes fidelity and robustness characteristics. The grey image watermark splits into two parts using four bits MSBs and four bits LSBs of each pixel. Discrete Cosine Transform (DCT) coefficients of these MSBs and LSBs values are embedded into the middle singular value of each block having size 4 × 4 of the host image’s one level Discrete Wavelet Transform (DWT) sub-bands. The reason for incorporating Arnold Cat Map in the proposed scheme is to encode the watermark image before embedding it in the host image. The proposed scheme is a blind scheme and does not require the choice of scaling factor. Thus, the proposed scheme is secure as well as free from the false positive detection problem. The proposed watermarking scheme is tested for various malicious and non-malicious attacks. The experimental results demonstrate that the scheme is robust, imperceptible and secure to several attacks and common signal processing operations.     

一种新的基于奇异值分解的小波域盲水印*

目前,如何增强鲁棒性水印抵抗几何攻击尤其是旋转攻击的鲁棒性,仍是水印研究者研究的难点。为此,结合奇异值分解的特性和小波变换的优点,提出一种新的基于奇异值分解的小波域盲水印算法,对于常见的几何攻击具有很强的鲁棒性。首先对小波分解后的低频子带分块以提高水印的嵌入容量,再对各子块进行奇异值分解,将Arnold置乱后的水印嵌入到奇异值中,并使用量化方法增强水印的鲁棒性。实验表明,该算法对于常见的几何攻击特别是旋转攻击具有很强的鲁棒性,也能够抵抗JPEG2000压缩等信号处理。     

An adaptive color image watermarking using RDWT-SVD and artificial bee colony based quality metric strength factor optimization

Image watermarking has emerged as a useful method for solving security issues like authenticity, copyright protection and rightful ownership of digital data. Existing watermarking schemes use either a binary or grayscale image as a watermark. This paper proposes a new robust and adaptive watermarking scheme in which both the host and watermark are the color images of the same size and dimension. The security of the proposed watermarking scheme is enhanced by scrambling both color host and watermark images using Arnold chaotic map. The host image is decomposed by redundant discrete wavelet transform (RDWT) into four sub-bands of the same dimension, and then approximate sub-band undergoes singular value decomposition (SVD) to obtain the principal component (PC). The scrambled watermark is then directly inserted into a principal component of scrambled host image, using an artificial bee colony optimized adaptive multi-scaling factor, obtained by considering both the host and watermark image perceptual quality to overcome the tradeoff between imperceptibility and robustness of the watermarked image. The hybridization of RDWT-SVD provides an advantage of no shift-invariant to achieve higher embedding capacity in the host image and preserving the imperceptibility and robustness by exploiting SVD properties. To measure the imperceptibility and robustness of the proposed scheme, both qualitative and quantitative evaluation parameters like peak signal to noise ratio (PSNR), structural similarity index metric (SSIM) and normalized cross-correlation (NC) are used. Experiments are performed against several image processing attacks and the results are analyzed and compared with other related existing watermarking schemes which clearly depict the usefulness of the proposed scheme. At the same time, the proposed scheme overcomes the major security problem of false positive error (FPE) that mostly occurs in existing SVD based watermarking schemes.     

Pair-wise path key establishment in wireless sensor networks

When sensor networks deployed in unattended and hostile environments, for securing communication between sensors, secret keys must be established between them. Many key establishment schemes have been proposed for large scale sensor networks. In these schemes, each sensor shares a secret key with its neighbors via preinstalled keys. But it may occur that two end nodes which do not share a key with each other could use a secure path to share a secret key between them. However during the transmission of the secret key, the secret key will be revealed to each node along the secure path. Several researchers proposed a multi-path key establishment to prevent a few compromised sensors from knowing the secret key, but it is vulnerable to stop forwarding or Byzantine attacks. To counter these attacks, we propose a hop by hop authentication scheme for path key establishment to prevent Byzantine attacks. Compared to conventional protocols, our proposed scheme can mitigate the impact of malicious nodes from doing a Byzantine attack and sensor nodes can identify the malicious nodes. In addition, our scheme can save energy since it can detect and filter false data not beyond two hops.     

An SVD-based image watermarking in wavelet domain using SVR and PSO

The paper presents a novel blind watermarking scheme for image copyright protection, which is developed in the discrete wavelet transform (DWT) and is based on the singular value decomposition (SVD) and the support vector regression (SVR). Its embedding algorithm hides a watermark bit in the low–low (LL) subband of a target non-overlap block of the host image by modifying a coefficient of U component on SVD version of the block. A blind watermark-extraction is designed using a trained SVR to estimate original coefficients. Subsequently, the watermark bit can be computed using the watermarked coefficient and its corresponding estimate coefficient. Additionally, the particle swarm optimization (PSO) is further utilized to optimize the proposed scheme. Experimental results show the proposed scheme possesses significant improvements in both transparency and robustness, and is superior to existing methods under consideration here.     

A copyright protection scheme for digital images using visual cryptography technique

A robust copyright protection scheme for digital image is proposed in the paper. In the proposed scheme, the watermark does not require to be embedded into the protected image but is used to generate a secret image and a public image by using the visual cryptography technique. Then the secret image is registered to certified authority (CA) for further protection. In the step of watermark extraction, the watermark can be acquired by performing exclusive-OR (XOR) operation between the secret image and the public image. The experimental results show that the proposed scheme not only can clearly verify the copyright of the digital image, but also is robust to withstand several image processing attacks such as JPEG lossy compression, cropping, noise adding, sharpening and blurring attacks.     

基于BTC与秘密共享的图像水印算法

结合块截短编码与秘密共享,提出一种新的鲁棒图像水印算法。该算法利用BTC编码由原图像构建特征共享,利用水印图像与特征共享一起生成私有共享。由待验证图像构建的特征共享与私有共享一起恢复水印图像。私有共享的生成与特征共享有关,可实现对同一图像的多水印注册。特征共享的稳健性确保了算法的水印鲁棒性,水印嵌入没有引起图像质量的改变。实验结果表明该算法对一般信号处理攻击有较高的鲁棒性。     

A novel hybrid of DCT and SVD in DWT domain for robust and invisible blind image watermarking with optimal embedding strength

To optimize the tradeoff between imperceptibility and robustness properties, this paper proposes a robust and invisible blind image watermarking scheme based on a new combination of discrete cosine transform (DCT) and singular value decomposition (SVD) in discrete wavelet transform (DWT) domain using least-square curve fitting and logistic chaotic map. Firstly cover image is decomposed into four subbands using DWT and the low frequency subband LL is partitioned into non-overlapping blocks. Then DCT is applied to each block and several particular middle frequency DCT coefficients are extracted to form a modulation matrix, which is used to embed watermark signal by modifying its largest singular values in SVD domain. Optimal embedding strength for a specific cover image is obtained from an estimation based on least-square curve fitting and provides a good compromise between transparency and robustness of watermarking scheme. The security of the watermarking scheme is ensured by logistic chaotic map. Experimental results demonstrate the better effectiveness of the proposed watermarking scheme in the perceptual quality and the ability of resisting to conventional signal processing and geometric attacks, in comparison with the related existing methods.     

A new robust reference watermarking scheme based on DWT-SVD

This paper presents a new semi-blind reference watermarking scheme based on discrete wavelet transform(DWT) and singular value decomposition(SVD) for copyright protection and authenticity. We are using a gray scale logo image as watermark instead of randomly generated Gaussian noise type watermark. For watermark embedding, the original image is transformed into wavelet domain and a reference sub-image is formed using directive contrast and wavelet coefficients. We embed watermark into reference image by modifying the singular values of reference image using the singular values of the watermark. A reliable watermark extraction scheme is developed for the extraction of watermark from distorted image. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. We show that the proposed scheme also stands with the ambiguity attack also.     

Secure and imperceptible digital image steganographic algorithm based on diamond encoding in DWT domain

This paper presents a new efficient embedding algorithm in the wavelet domain of digital images based on the diamond encoding (DE) scheme. Current discrete wavelet transform (DWT) steganography adds an unacceptable distortion to the images and is considered as an ineffective in terms of security. Applying the DE scheme to the current DWT steganographic methods solves the problems of these methods, and reduces the distortion added to the images, and thus improves the embedding efficiency. The proposed algorithm first converts the secret image into a sequence of base-5 digits. After that, the cover image is transformed into the DWT domain and segmented into 2?×?1 coefficient pairs. The DE scheme is used then to change at most one coefficient of each coefficient pair to embed the base-5 digits. Experimental results depict that the proposed algorithm is more efficient in embedding compared to other methods in terms of embedding payload and image quality. Moreover, the proposed algorithm is attacked by well-known steganalysis software. Results are showing that the proposed algorithm is secure against the powerful universal steganalyzer “ensemble classifier” and the histogram attack. The results also reveal that the proposed algorithm is robust against different image processing attacks such as compression, added noise, and cropping attacks.