一种基于DWT_SVD的抗几何攻击彩色图像水印算法

针对传统离散小波变换(DWT)水印算法不能较好地抵抗几何攻击的缺点,提出了一种基于离散小波变换(DWT)和奇异值分解(SVD)相结合的彩色图像水印新算法。首先对原始彩色载体图像进行RGB三基色分解,然后进行离散小波变换,再选取四个子块的四分之一重构成新子块,并进行二次离散小波变换,最后对其低频部分进行奇异值分解嵌入水印信息,得到嵌入水印的彩色图像。实验结果表明,该算法能够较好地抵抗诸如高斯噪声、椒盐噪声、压缩等常规攻击,并对大角度旋转、任意角度旋转、剪切加旋转等几何攻击也表现出了较强的鲁棒性,其总体性能明显优于传统的DWT水印算法。     

Local quaternion PHT based robust color image watermarking algorithm

It is a challenging work to design a robust localized color image watermarking scheme against desynchronization attacks. There are two main drawbacks indwelled in current localized color image watermarking: firstly, the pure gray-based feature points detectors were utilized, in which the important color information is ignored. Secondly, the watermarking algorithms were designed mainly to mark the image luminance component only, in which the significant color channels correlation are neglected. In this paper, we propose a robust color image watermarking algorithm using local quaternion PHT (Polar Harmonic Transform), which is invariant to various noises, local geometric transformations, and color variations. Firstly, the stable color image feature points are extracted by using new color image feature point detector, in which the SIFER (Scale-Invariant Feature detector with Error Resilience) detector and color invariance model are incorporated. Then, the affine invariant local regions are built adaptively according to local image content variation. Finally, the digital watermark is embedded into the local regions by modulating the invariant quaternion PHT modulus coefficients. Experiments are carried out on a color image set collected from Internet, and the extensive experimental works have shown that the proposed color image watermarking is not only invisible and robust against common image processing operations such as median filtering, noise adding, and JPEG compression, but also has conquered those challenging desynchronization attacks.     

一种鲁棒的彩色图像多功能水印算法

首先转换彩色图像的颜色空间抽取相应的灰度图像,再对灰度图像进行提升小波分解,在分解过程中利用图像压缩操作,引起近半数的小波系数增大,另一半系数减小,基于系数增减特征实现版权水印和消费者数字指纹的同时嵌入,从而获得版权认证和盗版追踪的双重功能。仿真实验表明该算法具有良好的鲁棒性和不可感知性。     

一种基于统计量化的抗几何攻击图像水印算法

依据图像受到几何攻击时亮度值统计特性不变原理提出了一种基于统计量化的抗几何攻击图像水印算法。用二值序列作为水印,水印嵌入时,首先选取一段亮度值范围,然后根据一定的步长将其划分为小区间,每一水印位对应一区间,最后对亮度值进行量化,使每个区间的像素都被量化到一个亮度值上。水印提取时,首先统计每个亮度值的像素个数,然后按照嵌入时的方法选取亮度范围并且划分区间,从每个区间提取一位水印信息。实验表明,这种方法对图像缩放、旋转和剪切等几何攻击有很强的鲁棒性,对中值滤波、噪声等常规攻击也具有较强鲁棒性。     

一种基于彩色图像的双重水印算法

针对传统水印算法功能单一,抗几何攻击能力较弱的问题,提出了一种基于离散小波变换(DWT)、奇异值分解(SVD)、离散余弦变换(DCT)和HSV空间模型的彩色图像双重水印算法.该算法基本思想是在彩色载体图像中先后嵌入可见水印和不可见水印.根据HSV 空间模型和DCT变换实现二值可见水印自适应嵌入,用来标识版权;通过DWT和SVD变换实现不可见彩色水印的嵌入,用于加强版权保护,利用Zernike矩进行旋转校正.实验结果表明,该算法在保证图像质量的前提下,可见水印具有较好的视觉可见性,不可见水印的抗几何攻击能力得到了提升.双重水印相互作用,功能互补提高了水印的版权保护功能.     

一种基才DWT-DCT变换强鲁棒性的数字水印算法

提出一种基于DWT-DCT的新的数字图像水印算法。该算法充分利用离散小波变换多分辨率特性和离散余弦变换能量压缩特性．综合两种变换的优点。在嵌入时,先对宿主图像进行DWT变换,得到4个子带。选择HL子带进行DCT变换．然后将加密后的水印嵌入DCT变换后得到子带中频系数。为获得较强的安全性,在嵌入前先对水印进行混沌加密。试验结果表明基于DWT-DCT联合的水印算法具有较强的不可见性,对常见的攻击具有较强的鲁棒性。     

一种基于DWT-DCT变换强鲁棒性的数字水印算法

提出一种基于DWT-DCT的新的数字图像水印算法.该算法充分利用离散小波变换多分辨率特性和离散余弦变换能量压缩特性,综合两种变换的优点.在嵌入时,先对宿主图像进行DWT变换,得到4个子带.选择HL子带进行DCT变换,然后将加密后的水印嵌入DCT变换后得到子带中频系数.为获得较强的安全性,在嵌入前先对水印进行混沌加密.试验结果表明基于DWT-DCT联合的水印算法具有较强的不可见性,对常见的攻击具有较强的鲁棒性.     

A novel image watermarking scheme against desynchronization attacks by SVR revision

In digital image watermarking, the watermark’s vulnerability to desynchronization attacks has long been a difficult problem. On the basis of support vector regression (SVR) theory and local image characteristics, a novel image watermarking scheme against desynchronization attacks by SVR revision is proposed in this paper. First, some pixels are randomly selected and the sum and variance of their neighboring pixels are calculated; second, the sum and variance are regarded as the training features and the pixel values as the training objective; third, the appropriate kernel function is chosen and trained, a SVR training model will be obtained. Finally, the sum and variance of all pixels’ neighboring pixels are selected as input vectors, the actual output can be obtained by using the well-trained SVR, and the digital watermark can be recovered by judging the output vector. Experimental results show that the proposed scheme is invisible and robust against common signals processing such as median filtering, sharpening, noise adding, and JPEG compression, etc., and robust against desynchronization attacks such as rotation, translation, scaling, row or column removal, shearing, local random bend, etc.     

一种对图像剪切具有鲁棒性的数字水印算法

该文提出了一种新的基于DCT变换的图像数字水印嵌入和检测算法,该算法可以抵御图像剪切等几何袭击,且水印的检测不需原始图像,仿真结果证实了所提方法的有效性。     

Secure and robust host-adapted color image watermarking using inter-layered wavelet-packets

This work presents a secure and robust color image watermarking for copyright protection applications, that is based on exploiting the multi-spectral properties of the primary color components of the RGB image. The proposed scheme employs the interconnection between the subbands of the primary color components in the wavelet-packet domain. The scheme is constructed to be adaptive, in the sense that the watermark bits are embedded in safe locations, depending on the inter-layer energy of coefficients in the wavelet-packets. The scheme immunity to attacks is improved by applying a two-level security procedure. To validate the high performance of the proposed scheme, several experimental tests were conducted and a comparative analysis was provided. The obtained results have shown improved watermarking robustness against a wide range of attacks while preserving a high watermarking imperceptibility.     

A robust region-adaptive dual image watermarking technique

Despite the progress in digital image watermarking technology, the main objectives of the majority of research in this area remain to be the improvement in robustness to attack. In this paper, a novel watermarking technique is proposed using a region-adaptive approach to further improve upon criteria. Watermark data is embedded on different regions of the host image using a combination of Discrete Wavelet Transform and Singular Value Decomposition techniques. The technique is derived from an earlier hypothesis that the robustness of a watermarking process can be improved by using watermark data which frequency spectrum not dissimilar to that of the host data. To facilitate this, the technique utilises dual watermarking technologies and embed parts of the watermark images into selected regions in the host image. Our experiment shows our technique has improved the robustness of the watermark data to image processing attacks and geometric attacks, thus validating the earlier hypothesis.     

A feature-based robust digital image watermarking scheme

A robust digital image watermarking scheme that combines image feature extraction and image normalization is proposed. The goal is to resist both geometric distortion and signal processing attacks. We adopt a feature extraction method called Mexican hat wavelet scale interaction. The extracted feature points can survive a variety of attacks and be used as reference points for both watermark embedding and detection. The normalized image of an image (object) is nearly invariant with respect to rotations. As a result, the watermark detection task can be much simplified when it is applied to the normalized image. However, because image normalization is sensitive to image local variation, we apply image normalization to nonoverlapped image disks separately. The disks are centered at the extracted feature points. Several copies of a 16-bit watermark sequence are embedded in the original image to improve the robustness of watermarks. Simulation results show that our scheme can survive low-quality JPEG compression, color reduction, sharpening, Gaussian filtering, median filtering, row or column removal, shearing, rotation, local warping, cropping, and linear geometric transformations.     

一种基于量化的图像水印方案

本文提出一种图像自适应的扩频水印方案，利用量化-替换过程将水印嵌到图像DCT域的中高频系数上，为保证水印的鲁棒性和透明性，根据视觉模型自适应地确定水印的量化区间，在水印检测时不需要参考原图。对水印图像的攻击实验表明：算法对噪声干扰及常见的图像处理技术具有较好的鲁棒性。     

一种基于图像特征的鲁棒性数字水印算法

提出了一种新的抗几何攻击的鲁棒性数字水印嵌入算法.采用Harris算子提取最健壮的特征点来估计图像可能遭受的几何攻击的参数,水印的嵌入则在满足不可察觉性的条件下遍布整个空间域.为获得最健壮特征点(MRFP),文中采用了一种自适应的特征点提取算法,通过对数字图像的预攻击处理,自适应地调整Harris探测器的阈值,来获得特定数目的MRFP.仿真结果表明,本算法对旋转、缩放、平移等几何攻击都具有很好的鲁棒性,对一般的图像处理如JPEG压缩、低通滤波、噪声等攻击也具有较好的抵抗性能.     

A new algorithm of blind color image watermarking based on LU decomposition

This paper proposes a new algorithm of blind color image watermarking based on LU decomposition. Because of the first column the second row element and the first column the third row element of the lower triangular matrix, which obtained by LU decomposition, have higher similarity, and the color image watermark can be embedded into these elements by slightly modifying rules, which can enhance the watermark invisibility. In addition, Arnold transform is applied to improve the watermark security and the Hash pseudo-random number algorithm based on MD5 is used to improve the watermark robustness. In extraction process, the watermark embedding strength and private key are needed to extract watermark information from the attacked host image with blind manner. Experiment results reveal that the proposed method outperforms other related methods in the aspects of the invisibility, robustness, embedding payload and computational complexity.     

基于小波变换的彩色图像数字水印新算法

提出了一种将灰度图像嵌入到原始彩色图像中的新数字水印算法.对RGB色彩空间彩色图像的绿色分量和蓝色分量进行haar小波变换.低频系数经过量化,将经过Arnold置乱后的灰度水印图像的位平面嵌入到低频子带.水印提取不需要原始载体图像.实验结果表明,该彩色图像数字水印算法不仅具有较好的透明性,而且对诸如叠加噪声、JPEG压缩、平滑滤波、几何剪切、图像增强和马赛克效果等攻击均具有较好的鲁棒性.     

Geometric attacks on image watermarking systems

Synchronization errors can lead to significant performance loss in image watermarking methods, as the geometric attacks in the Stirmark benchmark software show. The authors describe the most common types of geometric attacks and survey proposed solutions.     

Robust image watermarking against local geometric attacks using multiscale block matching method

This paper presents an image registration algorithm against the local geometric attack which is recently considered as the public enemy of most watermarking schemes. The watermark is embedded and retrieved using an amplitude modulation watermarking scheme. This work gives consideration to all the fidelity, robustness, and capacity. Moreover, the watermark bits act as implicit anchors to help correct local geometric distortions. In the proposed registration algorithm, an automatically multi-scaled neighborhood-matching approach is used to quickly and efficiently estimate local displacement, and a multi-resolution framework is superimposed to estimate both small and large local geometric distortions. Experimental results demonstrate the robustness and efficiency of the proposed algorithm.     

一种半脆弱性数字图像水印算法

本文基于JPEG有损压缩提出了一种半脆弱性数字图像水印算法。实验测试表明,所提出的算法不会明显影响图像的主客观质量,对JPEG有损压缩具有一定的顽健性,可以有效地进行篡改检测,达到检测和标示图像内容真实性的目的。