Secure watermarking scheme against watermark attacks in the encrypted domain

The homomorphic cryptosystems create a great opportunity for secure signal processing (SSP). Watermarking in the encrypted domain provides a promising solution to the security of watermarking. However, the robust performance of the watermarking scheme in the encrypted domain should be carefully considered. In this paper, we propose a robust watermarking scheme in the encrypted domain, which protects the original images from the third party embedders. The hybrid discrete wavelet transform (DWT) and discrete cosine transform (DCT) based method improves the robust performance of the encrypted domain watermarking scheme. The watermark extraction can be performed on both the plaintext and the encrypted domains. We also give an estimation of the expanding factor after watermark embedding in the encrypted domain. At last, we discuss the watermark attacks that are available in the encrypted domain. Taking Haar wavelet transform for example, we conduct the experiments on the visual quality and the robustness of our watermarking scheme, which demonstrate that the entire performance is satisfactory.     

Block-based SVD image watermarking in spatial and transform domains

The idea of this paper is to implement an efficient block-by-block singular value (SV) decomposition digital image watermarking algorithm, which is implemented in both the spatial and transforms domains. The discrete wavelet transform (DWT), the discrete cosine transform and the discrete Fourier transform are exploited for this purpose. The original image or one of its transforms is segmented into non-overlapping blocks, and consequently the image to be inserted as a watermark is embedded in the SVs of these blocks. Embedding the watermark on a block-by-block manner ensures security and robustness to attacks such like Gaussian noise, cropping and compression. The proposed algorithm can also be used for colour image watermarking. A comparison study between the proposed block-based watermarking algorithm and the method of Liu is performed for watermarking in all domains. Simulation results ensure that the proposed algorithm is more effective than the traditional method of Liu, especially when the watermarking is performed in the DWT domain.     

基于DWT-QDFT的硬拷贝彩色图像全息水印

提出了一种基于离散小波变换(DWT)及四元数傅里 叶变换(QDFT)的鲁棒性全息水印算法。首先对RGB彩色图像的三个色彩分量分 别做DWT,取变换后的3个低频部分组成纯四元数矩阵;随后对其进行QDFT ,将全息水印通过替代QDFT的实部的中频系数进行嵌入,再经过逆QDFT及小波重构得到含有 水印的彩 色图像。攻击测试结果表明,本文算法对于常规的信号处理有很好的鲁棒性;打印扫描实验 证明,本文算法具有抵 抗硬拷贝攻击的能力。四元数傅立叶变换的引入,实现了小波低频系数的嵌入保证了算法的 鲁棒性,同时 又结合了四元数在处理彩色图像中的优势,双变换域的采用与全息方法的结合实现了算法应 用于硬拷贝彩 色图像中鲁棒性及不可见性之间的平衡。本文全息水印方案可以应用于印品水印防伪领域。     

基于视觉显著性和置乱技术的小波域鲁棒性水印算法

用于版权认证的数字水印技术应满足安全性.鲁棒性和不可见性.为满足此三方面的要求,提出了一种基于视觉显著性和置乱技术的小波域鲁棒性水印算法.算法利用Arnold变换实现水印图像的置乱处理,通过小波空频分解,根据计算载体小波系数显著性指标确定水印的嵌入强度,最后进行小波系数融合嵌入.实验结果表明,文中算法能够抵抗常见攻击手段,具有较高的安全性、鲁棒性和不可见性.     

Robust digital watermarking algorithm based on continuous hyperchaotic system and discrete wavelet transform

Many digital watermarking methods have been pro-posedin the last fewyears[1 ,3].It is a tradeoff problemsince whenthe robustness of a watermarkincreases ,theperceptual quality of the contents will be degraded.Hence,the main goal of i mproving a watermarki…     

Robust image watermarking based on multiband wavelets and empirical mode decomposition.

In this paper, we propose a blind image watermarking algorithm based on the multiband wavelet transformation and the empirical mode decomposition. Unlike the watermark algorithms based on the traditional two-band wavelet transform, where the watermark bits are embedded directly on the wavelet coefficients, in the proposed scheme, we embed the watermark bits in the mean trend of some middle-frequency subimages in the wavelet domain. We further select appropriate dilation factor and filters in the multiband wavelet transform to achieve better performance in terms of perceptually invisibility and the robustness of the watermark. The experimental results show that the proposed blind watermarking scheme is robust against JPEG compression, Gaussian noise, salt and pepper noise, median filtering, and ConvFilter attacks. The comparison analysis demonstrate that our scheme has better performance than the watermarking schemes reported recently.     

基于ICA的智能数字水印技术

该文提出了一种基于智能信息分析方法--独立分量分析的智能数字水印新算法。水印嵌入之前先对其进行预处理,嵌入过程可以在图像任意作用域中实现,并给出了小波域中的一种闭环嵌入方法。水印嵌入的强度由小波域视觉模型决定。在不需要任何原始图像、水印和攻击类型等信息的情况下,该算法不仅可以检测到水印而且可以完全提取水印,实现了真正意义上的水印盲检测,并对多个水印嵌入的情况也可以进行水印提取。水印检测的精确程度取决于图像与水印之间的独立性以及所采用的密钥。实验过程中攻击由通用水印测试软件Stirmark产生,实验数据证明本文提出的水印算法对Stirmark提供的各种攻击剪切、滤波、图象压缩、删行、删列、几何攻击以及多种攻击同时存在时都具有很好的鲁棒性。     

基于变换域的数字水印技术

数字水印技术是将信息隐藏从而实现多媒体数据的版权保护,数字水印的研究主要是所提出的算法具有更好的不可见性和鲁棒性。提出了2种不同的变换域方法:一种是基于DCT域的水印算法,水印信息取自二值签名图像;另一种是基于小波分解的数字水印算法,采用服从高斯分布的随机数作为水印信息。实验结果表明,这2种水印算法具有良好的性能,实现的水印具有不可见性,而且对于常见的图像处理具有很好的鲁棒性。     

Robust and secure fractional wavelet image watermarking

This paper presents an efficient fractional wavelet transform (FWT) image watermarking technique based on combining the discrete wavelet transform (DWT) and the fractional Fourier transform (FRFT). In the proposed technique, the host image is wavelet transformed with two resolution levels, and then, the middle frequency sub-bands are FRFT transformed. The watermark is hidden by altering the selected FRFT coefficients of the middle frequency sub-bands of the 2-level DWT-transformed host image. Two pseudo-random noise (PN) sequences are used to modulate the selected FRFT coefficients with the watermark pixels, and inverse transforms are finally applied to get the watermarked image. In watermark extraction, we just need the same two PN sequences used in the embedding process and the watermark size. The correlation factor is used to determine whether the extracted pixel is one or zero. The proposed fractional wavelet transform (FWT) image watermarking method is tested with different image processing attacks and under composite attacks to verify its robustness. Experimental results demonstrated improved robustness and security.     

A Novel Algorithm for Robust Audio Watermarking in Wavelet Domain

With the sharp blossoming of the Internet, itbecomes more and more important to protect theintelligent property rights (IPR). Watermarking is aneffective solution. It takes advantage of the redundancyof the human visual system (HVS) and auditory system(HAS) to identify the copyright by embedding somesecret information relevant to IPR holders. The invisible watermarking algorithm shouldsatisfy the demands on imperceptivity, low complexity,robustness, determinacy and safety. However,imperc…     

基于DWT域的音频水印算法研究

论述了DWT(离散小波变换)域中的一种音频水印的嵌入和提取算法,此算法能够实现盲检测,并在Matlab软件中进行了仿真实验。实验结果表明,此算法具有较好的不可感知性,并且对叠加噪声、重采样、重量化、回声、MP3压缩等攻击具有较好的鲁棒性。     

离散小波变换和奇异值分解相融合的彩色图像水印算法

为加强数字多媒体的版权保护,提出了一种结合离散小波变换和奇异值分解相融合的彩色图像水印算法(DWT-SVD).首先对彩色数字载体图像进行小波分解,并对其小波系数进行奇异值分解;然后对水印信息采用Arnold进行置乱,并进行奇异值分解;最后将水印信息的奇异值嵌入到彩色图像的小波系数奇异值中,并对水印嵌入强度进行调节.仿真结果表明,DWT-SVD可以检测到完整的水印信息,具有良好的不可见性,对各种攻击具有较强的鲁棒性.     

基于Contourlet-DCT混合变换的零水印算法

为提高水印图像的安全性,并解决水印嵌入时鲁棒性与不可见性之间的矛盾,提出了一种基于Contourlet-DCT混合变换的零水印算法.首先,利用二值水印图像自身不同的像素值对两个混沌序列进行调制加密,并将调制后的结果作为加密的水印图像.接下来对载体图像依次进行Contourlet与DCT变换从中提取能量特征,再对提取的特征进行奇异值分解,选取其中最大的奇异值重组特征矩阵,最后把特征矩阵与加密后的水印图像结合生成注册水印.为验证算法的有效性,将该算法与传统的小波域零水印算法进行了比较,结果表明,混合域零水印算法在多项攻击测试中的鲁棒性均优于后者.     

Multipurpose image watermarking algorithm based on multistage vector quantization.

The rapid growth of digital multimedia and Internet technologies has made copyright protection, copy protection, and integrity verification three important issues in the digital world. To solve these problems, the digital watermarking technique has been presented and widely researched. Traditional watermarking algorithms are mostly based on discrete transform domains, such as the discrete cosine transform, discrete Fourier transform (DFT), and discrete wavelet transform (DWT). Most of these algorithms are good for only one purpose. Recently, some multipurpose digital watermarking methods have been presented, which can achieve the goal of content authentication and copyright protection simultaneously. However, they are based on DWT or DFT. Lately, several robust watermarking schemes based on vector quantization (VQ) have been presented, but they can only be used for copyright protection. In this paper, we present a novel multipurpose digital image watermarking method based on the multistage vector quantizer structure, which can be applied to image authentication and copyright protection. In the proposed method, the semi-fragile watermark and the robust watermark are embedded in different VQ stages using different techniques, and both of them can be extracted without the original image. Simulation results demonstrate the effectiveness of our algorithm in terms of robustness and fragility.     

一种有效抵抗裁剪攻击的小波域盲水印算法

该文提出了一种有效抵抗裁剪攻击的小波域盲水印算法,能从小的图像块上检测出水印。首先将图像进行小波变换,选择两个所需要的子带,利用相邻特征平均值和奇偶判决法在两个子带上各自重复内嵌一半水印,在水印检测过程中不需要原始图像。实验结果表明,该算法具有较好的透明性,对各种攻击有较强的鲁棒性,尤其是明显增强了小波域水印在面临裁剪攻击和联合攻击时的鲁棒性。     

自适应的混合域音频水印新算法

本文结合小波包变换和离散余弦变换，提出了一种基于听觉模型的混合域自适应音频盲水印算法，在不引入听觉失真的前提下，实现了自适应的水印嵌入。算法首先对音频信号进行小波包分解，使得分解后的子带更接近人耳临界频带。其次对每个子带的小波包系数进行离散余弦变换，计算出子带掩蔽阈值。根据子带掩蔽阈值自适应的选取噪声敏感度小的音频段作为水印嵌入段，选取功率值低于掩蔽阈值的频域系数作为水印嵌入位置，同时采用噪声掩蔽比调整水印嵌入强度。二值水印图像通过量化索引调制的方法嵌入到音频信号的中低频系数中，提取水印时不需要原始音频载体。本算法在水印容量、不可感知性和鲁棒性之间达到了很好的平衡，水印容量在576.7bps到689.5bps之间，算法对添加噪声、重新量化、重新采样、低通滤波和MP3压缩均具有很好的鲁棒性。      

一种基于DWT-DCT变换域的全息水印技术

在研究傅里叶全息技术基础上,提出了一种结合离 散小波变换和离散波变换(DWT-DCT)变换的彩色图像数字水印算法,使得水印 拥有强鲁棒性和不可见性。首先,对水印信息进行傅里叶变换,并生成全息水印图; 其次,将载体图 像在RGB空间内的蓝色B分量进行小波分解,对其低频部分进行DCT;最后, 将水印全息图嵌入其高频系数 中。实验结果发现,以k=0.05的强度嵌入水印后,含水印图像的峰值 信噪比(PSNR)达到47,能有效抵抗 信号处理和裁切攻击,同时提取出的水印和原始水印的相似性(NC值)能保持在0. 75以上,说明本文水印 算法有较强的鲁棒性和不可见性。本文算法能够抵抗裁切、滤波、噪声和JPEG压缩攻击,可 用于数字图像版权保护方面。     

A new video watermarking algorithm based on 1D DFT and Radon transform

In this paper, we propose a new video watermarking algorithm based on the 1D DFT (one-dimensional discrete Fourier transform) and Radon transform. The 1D DFT for a video sequence generates an ideal domain, in which the spatial information is still kept and the temporal information is obtained. With detailed analysis and calculation, we choose the frames with highest temporal frequencies to embed the fence-shaped watermark pattern in the Radon transform domain of the selected frames. The adaptive embedding strength for different locations keeps the fidelity of the watermarked video. The performance of the proposed algorithm is evaluated by video compression standard H.264 with three different bit rates; geometric attacks such as rotation, translation, and aspect-ratio changes; and other attacks like frame drop, frame swap, spatial filtering, noise addition, lighting change, and histogram equalization. The main contributions of this paper are the introduction of the 1D DFT along temporal direction for watermarking that enables the robustness against video compression, and the Radon transform-based watermark embedding and extraction that produces the robustness against geometric transformations. One of the most important advantages of this video watermarking algorithm is its simplicity and practicality.     

Discrete Multiwavelet–Based Video Watermarking Scheme Using SURF

This paper proposes a robust, imperceptible block‐based digital video watermarking algorithm that makes use of the Speeded Up Robust Feature (SURF) technique. The SURF technique is used to extract the most important features of a video. A discrete multiwavelet transform (DMWT) domain in conjunction with a discrete cosine transform is used for embedding a watermark into feature blocks. The watermark used is a binary image. The proposed algorithm is further improved for robustness by an error‐correction code to protect the watermark against bit errors. The same watermark is embedded temporally for every set of frames of an input video to improve the decoded watermark correlation. Extensive experimental results demonstrate that the proposed DMWT domain video watermarking using SURF features is robust against common image processing attacks, motion JPEG2000 compression, frame averaging, and frame swapping attacks. The quality of a watermarked video under the proposed algorithm is high, demonstrating the imperceptibility of an embedded watermark.     

Video Watermark Using Multiresolution Wavelet Decomposition

A novel technique for the video watermarking based on the discrete wavelet transform(DWT) is present. The intra frames of video are transformed to three gray image firstly, and then the 2th-level discrete wavelet decomposition of the gray images is computed, with which the watermark W is embedded simultaneously into and invert wavelet transform is done to obtain the gray images which contain the secret information. Change the intra frames of video based on the three gray images to make the intra frame contain the secret information. While extracting the secret information, the intra frames are transformed to three gray image, 2th-level discrete wavelet transform is done to the gray images, and the watermark W‘ is distilled from the wavelet coefficients of the three gray images. The test results show the superior performance of the technique and potential for the watermarking of video.