基于小波变换的数字水印及版权保护

数字水印技术是近年来关于版权保护方面研究的一个新课题,通常的水印是指嵌入在图像中的隐蔽的信息,作为数字图像的标签。通过复杂的水印嵌入方法可以防止非授权拷贝或对图像的其它攻击性操作。本文提出了基于块的小波变换下水印的嵌入和提取方法,使每一个水印像素隐藏在相应的图像块的中低频小波系数之中。利用本文的水印技术可以较好地解决版权争议等问题。理论分析和实验结果均证明了本文提出的方法是有效的和可行的。     

菲涅耳数字全息在图像加密中的应用

基于小波变换和光学菲涅尔变换原理,提出一种新的数字水印算法。首先,原始的水印图像经过离散菲涅尔变换转化成数字全息图,并对数字全息图进行灰度变换;再对宿主图像进行一层小波分解;最后将变换后的数字全息图嵌入到宿主图像较大的小波系数中。实验结果表明,该水印算法具有较强的鲁棒性,能抵抗较大的剪切、有损压缩和滤波等攻击。     

基于多规则小波变换的视频水印加密算法研究

通过对视频嵌入水印的安全性和鲁棒性的分析,采用了一种基于多规则小波变换的视频水印嵌入与提取算法.该算法首先对水印图像进行置乱加密增强其安全性,其次对视频帧和水印图像分别进行多层小波变换,最后根据不同的小波系数进行多规则水印嵌入.算法不仅充分利用了小波变换的多分辨特性,而且兼顾了水印的不可感知性和视频帧的鲁棒性.实验结果表明,该算法对高斯噪声、几何失真和压缩等具有良好的安全性和鲁棒性.     

一种基于离散余弦变换与奇异值分解的数字图像水印算法

结合奇异值分解（SVD）和离散余弦变换（OCT）的特点,提出了一种基于离散余弦交换与奇异值分解的数字图像水印算法.该算法能够很好地解决透明性和鲁棒性之间的矛盾.算法中采用经过置乱变换的灰度图作为水印,不仅增加了嵌入的信息量,而且提高了水印的安全性.实验结果表明,该算法不仅具有较好的透明性,而且对常见攻击如：叠加噪声、JPEG压缩、滤波以及几何攻击等具有较好的鲁棒性.     

一种基于提升方案小波和小波块的图像水印算法

数字水印技术是多媒体信息安全领域的一个重要研究课题。文章提出一种基于提升方案小波和小波块的图象水印算法。首先，利用提升方案小波对宿主图像和水印图像进行分解，同时利用小波系数的树结构，将宿主图像的小波系数块按纹理密度分成两类，并根据嵌入位置所隶属的小波块的纹理强弱，嵌入不同强度的水印信息，这在一定程度上保证了所嵌入水印在不可见性前提下的极大鲁棒性。实验结果验证了所提出算法的有效性。     

一种基于FFMPEG系统的视频水印算法

提出一种基于FFMPEG系统的MPEG-2视频水印算法,解决了视频水印中不可避免的视频编解码问题。将水印图像和水印属性转成二进制比特流,作为嵌入视频的水印信息,提取时不需预知水印的尺寸信息就能恢复。同时在每个嵌入帧的起始部位嵌入标志序列,识别已嵌入水印的帧提取水印,而无需重新进入编码过程。实验结果表明,这种方案实现便捷,省时高效,且具有较好的不可见性和鲁棒性。     

基于三维小波变换的视频水印嵌入与盲提取算法

为了寻求有效的数字媒体保护方法,该文提出了一种在三维小波变换域内基于二值运算的数字视频水印嵌入算法。为了实现水印的获取,提出了一种相应的水印盲提取算法。水印的嵌入与提取算法每次只对4帧图像进行小波分解,不仅充分利用了小波变换良好的空时多分辨特性,而且占用内存空间少、时延低,适合视频流的在线水印嵌入和提取,并易于硬件的实时实现。实验结果表明,该文所提出的视频水印算法对高斯噪声、MPEG编码、帧平均、帧抽取和帧置乱具有良好的鲁棒性。     

基于小波域低频系数的自适应盲视频水印算法

设计了一种基于小波域低频系数的自适应盲视频水印算法,先用Arnold变换对水印图像进行置乱加密,再对原始视频进行分帧处理并提取亮度分量,将水印信息嵌入到亮度分量三层离散小波变换的低频系数中,嵌入强度由低频系数自适应地选取.实验结果表明,水印的安全性和不可感知性很好,在抵抗噪声干扰、帧删除、帧剪切以及滤波等多种攻击时具有良好的稳健性.     

Robust Video Watermarking Using a Hybrid DCT-DWT Approach

In order to solve the limitations of the digital video watermarking algorithm, this paper proposes a new robust video watermarking algorithm using combining discrete cosine transform (DCT) and discrete wavelet transform (DWT) techniques. First of all, the video frames are randomly selected and then the DCT algorithm is applied to the selected video frames. After that, the first column of the selected video frames is scrambled using the Arnold algorithm. Furthermore, every column with 4 direct current (DC) coefficients is reshaped and transformed into four different sub-bands using the DWT technique. Next, the watermark is embedded into the approximation (LL) sub-band. The proposed algorithm is easy to carry out because it provides random frames with no special requirements for video frames. The experiment results indicate that this algorithm can resist against different kinds of watermarking attacks, such as the Gaussian filter attack and sharpen attack. In addition, it also illustrates that the proposed algorithm has a better result than some other watermarking algorithms.     

图像高逼真度的自适应盲水印算法

随着计算机和网络技术的飞速发展,数字图像、音频和视频产品越来越需要一种有效的版权保护方法,所谓数字水印就是一种嵌入到图像、视频或音频数据中的不可见标志,可以用于多媒体数据的版权保护、认证和标注等。该文提出了一个有效的自适应育水印算法,在水印检测过程中不需要原始图像。原始图像经小波变换后,选择内嵌水印所需要的子带,水印根据邻居特征平均值法和奇偶判决法内嵌到频域中所选择的子带上。实验结论和攻击测试表明,该文所提议的算法能得到高逼真度的加水印图像,对如 JPEG有损压缩、中值滤波、附加噪声、伸缩、裁剪等各种图像处理的攻击有较强的稳健性。     

基于双重水印加密和SVD的视频水印方案

针对视频水印的安全性,提出了一种基于双重水印加密和SVD的视频水印方案。该方法首先将水印图像经Arnold置乱,对置乱后的水印通过Chebyshev混沌映射进行加密,保障水印的安全性;然后,对视频关键帧进行三级小波分解,利用SVD对几何失真的不变性,将水印3次嵌入到LL3、HL3和LH3中。实验表明该方案对高斯噪声、MPEG压缩、剪切等具有较高的鲁棒性。     

基于自嵌入鲁棒双水印的图像认证算法

通过构造鲁棒零水印并鲁棒的嵌入到图像自身来实现完全盲检测的鲁棒水印方案,从而完成数字图像的全盲版权认证。首先利用整数小波变换构造鲁棒零水印:将原始图像进行三级整数小波变换,并将变换后获取的第三级低频子带(LL3)系数二值化来构造鲁棒零水印。然后利用一种基于奇异值分解(SVD,singular value decomposition)的鲁棒水印方案,将构造的鲁棒零水印嵌入到图像小波变换域低频子带(LL1)的分块奇异值分解的U矩阵的系数中。利用超混沌系统设计了随机置乱和加密方案。在鲁棒嵌入之前,先将二值零水印进行置乱分散并加密,增强了方案的鲁棒性和构造水印安的全性。实验结果证明了所提出的方案的有效性。     

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.     

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.     

基于帧间相关性的盲视频数字水印算法

提出了一种在原始视频中嵌入水印的算法。嵌入的水印由2部分组成:标志水印和信息水印。首先从一段原始视频里随机选出若干视频帧,在这些帧的像素平面亮度分量上固定位置嵌入标志水印,再根据密钥选取其他若干图像块在其离散余弦变换(DCT)直流系数中嵌入信息水印。然后在整段视频的每一小段中重复嵌入水印。提取水印时,只需从整段视频中截取足够包含完整信息水印的一小段视频,通过搜索标志水印快速地选出包含水印信息的帧。然后利用水印帧与前后相邻视频帧之间内容的高度相关性,得到嵌入水印位置像素值的估计,与包含水印信息帧相应位置做比较,提取出水印信息,实现了水印的盲提取。实验结果表明本算法能够抵抗压缩、缩放、帧删除/插入等各种攻击,具有较强的健壮性。     

基于独立分量分析的盲视频水印方案

本文提出一种新的盲视频水印方案.该方案利用独立分量分析方法根据相邻的视频帧提取相应的运动分量,并且把这些运动分量进行小波变换,采用邻近特征值平均法,将水印嵌入到运动分量中.运动分量是视频的重要特征,压缩的处理对于它的影响较小,因此可以提高鲁棒性.基于帧的运动分量的提取避免了基于块的重复性操作,小波域的水印嵌入可以将水印带来的影响分散到整个帧上,具有良好的不可见性.计算机仿真结果表明,该方法能够保证很好的视频质量,对于常见的视频处理有较好的鲁棒性,能够进行水印的盲检测,虚警概率小.     

Quantisation-based video watermarking in the wavelet domain with spatial and temporal redundancy

In this article we introduce a new public digital watermarking technique for video copyright protection working in the discrete wavelet transform domain. The scheme uses binary images as watermarks. These are embedded in the detail wavelet coefficients of the middle wavelet sub-bands. The method is a combination of spread spectrum and quantisation-based watermarking. Every bit of the watermark is spread over a number of wavelet coefficients with the use of a secret key. The resilience of the watermarking algorithm was tested against a series of eight different attacks using different videos. To improve the resilience of the algorithm we use error correction codes and embed the watermark with spatial and temporal redundancy. The proposed method achieves a very good perceptual quality with mean peak signal-to-noise ratio values of the watermarked videos of more than 40 dB and high resistance to a large spectrum of attacks.     

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.     

基于DWT SVD域的彩色图像水印算法

针对数字产品的版权保护问题,提出了一种结合整数小波变换（DWT）和矩阵奇异值分解（SVD）的彩色图像非盲水印算法。该算法首先对待处理图像的蓝色分量进行整数小波分解,再将得到的低频子带的小波系数矩阵进行奇异值分解,然后对水印灰度图像进行奇异值分解,水印图像的奇异值被嵌入到由源图像小波系数分解得到的奇异值中。经过奇异值分解逆变换及整数小波逆变换得到含水印图像。实验结果表明,该算法对加噪、滤波、JPEG压缩、剪切、缩放和旋转攻击均有较强的抵抗力,具有较好的实用价值。     

Hiding digital watermarks using multiresolution wavelet transform

In this paper, an image accreditation technique by embedding digital watermarks in images is proposed. The proposed method for the digital watermarking is based on the wavelet transform. This is unlike most previous work, which used a random number of a sequence of bits as a watermark and where the watermark can only be detected by comparing an experimental threshold value to determine whether a sequence of random signals is the watermark. The proposed approach embeds a watermark with visual recognizable patterns, such as binary, gray, or color image in images by modifying the frequency part of the images. In the proposed approach, an original image is decomposed into wavelet coefficients. Then, multi-energy watermarking scheme based on the qualified significant wavelet tree (QSWT) is used to achieve the robustness of the watermarking. Unlike other watermarking techniques that use a single casting energy, QSWT adopts adaptive casting energy in different resolutions. The performance of the proposed watermarking is robust to a variety of signal distortions, such as JPEG, image cropping, sharpening, median filtering, and incorporating attacks