基于DWT-SVD域的彩色图像自适应水印算法

为了保护数字彩色图像版权,提出了一种结合离散小波变换(DWT)和矩阵奇异值分解(SVD)的彩色图像自适应水印算法。其主要设计思想是:先将原RGB彩色图像的各颜色分量进行小波分解;再将得到的中、低频带的小波系数与原水印图像分别进行奇异值分解,水印信息的奇异值重复嵌入到三通道中、低频带的小波系数奇异值中,且利用临界视觉阈值与奇异值之间的关系对水印嵌入强度作自适应调节,从而达到增强水印鲁棒性和确保水印透明性的目的。本算法适用于二值及灰度水印,在二值水印的提取过程中需设定一个提取阈值,以保证提取水印的完整性。仿真结果说明本算法对水印系统的透明性与鲁棒性作了较好的协调,是一种较稳健的算法。     

An adaptive image watermarking algorithm based on perceptual model

An adaptive image watermarking algorithm based on Watson＇s perceptual model is proposed in this paper. The proposed watermarking algorithm fully considers image regional characteristic. First, the cover image is divided into different smooth regions according to its gray value. Then watermark adjustment factors of those different regions are calculated respectively based on Watson＇s perceptual model. The watermark is embedded by the adjustment factors at last. Experiments show that the proposed algorithm has excellent imperceptibility and has little influence upon the eigenvalue of the cover image.     

模糊自适应的彩色图像数字水印算法*

提出了一种基于离散余弦变换 (DCT)域的模糊自适应彩色图像水印算法.采用YUV彩色空间,以人类视觉系统(HVS)为基础,结合原始图像的特点,设计了模糊控制器,建立了合理的模糊规则,将水印信号以不同强度嵌入到彩色图像的Y、U、V分量的DCT系数中,实现了水印的自适应嵌入以及水印强度的动态调度.实验结果表明,该算法不仅具有很好的不可感知性,而且对剪切、滤波、噪声等攻击均具有较好的鲁棒性.     

基于DWT-SVD的图像盲水印研究

提出了一种新的基于离散小渡变换(DWT)与奇异值分解(SVD)相结合的数字图像水印算法.该算法将原始图像作小波分解并将小波分解得到的低频子带进行分块,对每一块进行奇异值分解后,选取每块中最大的奇异值通过量化的方法嵌入经过Arnold置乱后水印信息.水印的提取不需要原始图像,但受到密钥的限制,不知道密钥的人无法正确地恢复数字水印.实验结果表明,该算法具有较好的不可感知性、鲁棒性和安全性.     

Shearlet变换域内容自适应图像水印算法

提出了一种Shearlet变换域嵌入强度因子能随图像内容自适应的水印算法。算法首先利用Shearlet变换对图像内容稀疏表示选择性,找出符合人眼视觉特性要求的水印嵌入位置,然后依据图像内容自适应地计算出水印嵌入强度因子,较好地解决了鲁棒性与可见性之间的矛盾。实验结果表明,该算法能够抵抗各种攻击,具有强鲁棒性。     

基于ZUC与DWT-SVD的交换加密水印算法

为了有效解决多媒体数据在传输、存储过程中的安全及版权保护问题,提出基于祖冲之序列密码算法(zuc)与离散小波变换—奇异值分解(DWT-SVD)的交换加密水印算法.该算法基于奇异值不变性,将水印嵌入到奇异值中,通过ZUC算法分别对奇异值矩阵集合、奇异矩阵集合置换加密.水印嵌入操作与加密操作的先后顺序不影响含水印密文的生成,且从含水印密文和解密后的明文中都能提取完整的水印.实验表明,水印的不可见性较好,算法有较高的安全性并具有—定的鲁棒性.     

基于DWT-SVD与量化相结合的盲水印算法

提出了一种新的盲鲁棒水印算法,它充分利用了小波变换的多分辨特性和矩阵奇异值分解的能量稳定特性,通过量化的方法将二值水印嵌入到原始图像的低频区域中,在水印的提取过程中不需要原始图像参与。实验证明,该水印算法的鲁棒性较好,具有不可见性,比Sun算法的性能有所提高。     

Protecting ownership rights through digital watermarking

The Internet revolution is now in full swing, and commercial interests abound. As with other maturing media technologies, the focus is moving from technology to content, as commercial vendors and developers try to use network technology to deliver media products for profit. This shift inevitably raises questions about how to protect ownership rights. Digital watermarking has been proposed as a way to identify the source, creator, owner, distributor, or authorized consumer of a document or image. Its objective is to permanently and unalterably mark the image so that the credit or assignment is beyond dispute. In the event of illicit use, the watermark would facilitate the claim of ownership, the receipt of copyright revenues, or successful prosecution. Watermarking has also been proposed for tracing images that have been illicitly redistributed. In the past, the infeasibility of large-scale photocopying and distribution often limited copyright infringement, but modern digital networks make large-scale dissemination simple and inexpensive. Digital watermarking allows each image to be uniquely marked for every buyer. If that buyer makes an illicit copy, the copy itself identifies the buyer as the source     

结合均值调整整数变换的迭代自适应可逆图像水印算法

现有的均值调整整数变换可逆水印算法的阈值需人工选择,位置图生成策略不完备可能导致压缩后位置图数据过大,对嵌入矢量强制划分可能导致容量足够却无法嵌入。针对以上问题,提出一种结合均值调整整数变换的迭代自适应可逆图像水印算法。首先,根据负载数据大小以及整数矢量对峰值信噪比(PSNR)的影响,采用迭代自适应算法选择调整平移量以达到水印嵌入容量和嵌入载体视觉质量的平衡;然后,结合邻近像素值相近原则给出了完备位置图生成策略以提高位置图压缩性能;最后,采用分层有序嵌入策略将负载数据依次嵌入到最低、次低和第3低有效位以避免容量足够却无法嵌入的情况。实验结果表明,与传统均值调整整数变换可逆水印算法相比,所提算法无需预先设定阈值,但依然能保持大的嵌入容量,嵌入水印后掩体视觉质量更优,位置图生成策略性能优于传统均值调整整数变换可逆水印算法生成策略且压缩后的位置图数据更小,从而间接提高了嵌入容量,在实验样例上相对于比较算法,PSNR平均提高14.4%。     

基于DWT-SVD和Fibonacci变换的彩色图像盲水印算法

为提高水印鲁棒性,将离散小波变换(DWT)、奇异值分解(SVD)和斐波纳契(Fibonacci)变换结合,提出一种新的算法。首先,用Fibonacci变换对拟嵌入的水印进行置乱处理;然后,对宿主彩色图像R、G、B三个分量进行二级小波变换和基于4×4分块的奇异值分解,并用混沌序列选择若干对子块;最后,根据人类视觉系统(HVS)特性对三个分量分配嵌入量、确定嵌入强度,并通过修改每对子块最大奇异值来实现水印嵌入。实验结果表明本方案具有良好的水印不可见性和鲁棒性。     

Novel dynamic color image watermarking based on DWT-SVD and the human visual system

Multimedia Tools and Applications - In this paper, a novel dynamic color image watermarking based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. The...     

Digital image ownership authentication via camouflaged unseen-visible watermarking

In recent years, end users can easily capture digital images using several devices, such as smartphones, mobile devices and digital imaging cameras, allowing such images to be easily copied, manipulated, transmitted or format converted without any restrictions. This fact suggests the necessity to develop digital tools, such as digital watermarking, to solve the issues associated with copyright protection and ownership authentication of digital images. To claim the ownership of a digital image, we propose a camouflaged, unseen-visible watermarking technique based on luminance and texture properties in conjunction with an image enhancement criterion. The proposed method has some advantages over invisible and visible watermarking methodologies in terms of readability and imperceptibility of the watermark, respectively. The experimental results demonstrate that the proposed scheme is effective and applicable for digital images on a variety of topics, including natural scenes and man-made objects, both indoors and outdoors. A comparison with previously reported methods based on unseen-visible watermarking techniques is also provided.     

Medical image watermarking for ownership & tamper detection

Multimedia Tools and Applications - Image watermarking can provide ownership identification as well as tamper protection. Transform domain based image watermarking has been proven to be more robust...     

基于内容自适应小波域鲁棒公开数字水印算法

提出一种在小波域实现的基于内容自适应的鲁棒公开数字水印算法。该算法的特点在于：充分利用人眼视觉特性（HVS）、挖掘原始载体图像内容、实现数字水印嵌入阈值的智能调节和自适应嵌入、增强算法的透明性和鲁棒性。实验结果表明：该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、等攻击均具有较好的鲁棒性。     

一种自适应盲灰度水印算法

本文提出了一种基于余数条件稳定性的自适应盲水印算法，并将DC和AC系数结合进行水印的嵌入。使用余数设置的方法在四个系数中嵌入水印，将它们的余数关联起来。并利用视觉掩蔽效应自适应地选择嵌入强度，使得不可见性和鲁棒性得到很好的折中。通过对系数的重组，对灰度水印权值较高的位（高平面位）进行重点保护，使提取的水印质量得以提高。改进了通常在DC系数中嵌入水印是非盲算法和嵌入容量较小的缺陷，同时避免了DC系数改变过大引起的块效应。实验证明该算法取得了很好的效果。     

A blind medical image watermarking: DWT-SVD based robust and secure approach for telemedicine applications

Multimedia Tools and Applications - In this paper, a blind image watermarking scheme based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. In this scheme,...     

An imperceptible semi-blind image watermarking scheme in DWT-SVD domain using a zigzag embedding technique

Multimedia Tools and Applications - This research work presents a semi-blind image watermarking scheme based on transforms domain DWT-SVD using an efficient embedding technique. This scheme...     

一个分形图像水印算法的改进

改进了一个分形水印算法,它把二值版权图标嵌入到分形压缩的图像文件中。具体说,把宿主图像分成大小相同的不重叠的子块,对这些子块进行分形编码（采用正交分形编码方法）。这些子块按拼贴误差的大小进行降序排列,并根据宿主图像内容分成三个子列。按照新的量化嵌入公式,经Arnold变换置乱后的水印被强度不同地嵌入三个子列的子块的量化均值中,通过分形解码得到含水印图像。实验表明,该算法隐蔽性强,并对剪切、涂抹、加噪、滤波以及JPEG压缩等具有较强的鲁棒性。     

一种新的彩色图像盲水印算法*

在探讨了四元数及四元数矩阵奇异值分解性质的基础上,用四元数矩阵来表示彩色图像,彩色图像的每个像素用一个四元数来表示,从而实现了将彩色图像的各个分量作为一个整体进行运算的思想;对彩色图像的四元数矩阵奇异值分解后的性质进行了研究,得出将四元数矩阵分解的方法用于彩色图像水印的嵌入和提取的可行性,并提出一种基于四元数矩阵奇异值分解、旋转和共轭运算的彩色图像盲水印算法进行验证。通过实验和对比表明,该算法具有良好的性能,能较好地抵抗常见的攻击。     

灰度图像水印的自适应二维数字水印算法

本文提出了一种采用可视灰度图像作为水印信号,根据人类视觉掩体特性进行分类,并结合系数自身的特点,通过修改DCT域中低频和次低频系数来嵌入不同强度水印的算法。实验结果表明,应用所提出的算法实现的水印对常见图像处理和噪声干扰具有很好的稳健性。