基于色调处理技术的图像认证算法

基于色调处理技术,该文给出了一种有效可行且具有自修复能力的图像认证算法。首先,基于误差扩散色调处理技术将水印图像4bit色调量化,井依据混沌置乱算子,将色调结果置乱,然后构造平均误差最小的特征集合C,最后依据误差扩散数据隐藏算法将置乱后水印图像隐藏于原始图像中;在认证端,从接收到的图像提取其中所隐藏水印信息并进行逆置乱,比较接收到的图像和反置乱后的隐藏信息,判断内容发生变化的位置,并依据所提取的水印信息修复被篡改图像。实验结果表明,该算法对删除、替换、篡改等破坏图像内容的恶意操作有精确的检测和定位,以及自修复能力。     

基于可见水印的课件版权保护研究

互联网络的快速发展推动了网络课程和远程教育的广泛应用。课件是一种重要的网络教学资源,为保护制作者的权益,将可见水印和可逆数据隐藏技术相结合应用于课件版权保护系统中。版权通告采用了自适应图像特性的可见水印技术,为能按需还原图像采用了基于直方图的可逆数据隐藏技术。该算法使版权水印标识在不影响图像使用的基础上清晰可见,并且可去除水印,完全恢复出原始图像。实验结果验证了该算法应用于课件版权保护的有效性。     

应用于实时通信版权保护的BTC图像水印技术

现有BTC图像水印方案多为脆弱水印技术或数据隐藏技术,不能应用于数字图像版权保护.为保护数字电视实时通信图像版权,结合Haar小波变换,提出一种稳健的BTC域图像水印算法.算法首先对载体图像BTC域两重建电平进行Haar小波变换,然后通过修改低频系数以嵌入稳健水印.水印提取时无须原始载体图像参与.仿真实验表明,算法具有...     

基于异或运算和图像融合的盲数字水印嵌入和检测方法

数字水印隐藏是将一个版权识别标志(水印信号)嵌入到图像中的技术。本文提出的一种新的隐藏水印的方法是将水印看作是二值图像,运用小波变换,异或运算,图像融合的方法以及中值滤波来隐藏和提取数字水印。这种方法的优点是不需要原始图像就可以提取出水印图像,可以加密码,对椒盐噪声,剪切攻击具有鲁棒性。     

基于队列置乱的小波域盲水印算法

随着Internet的普及和多媒体技术的发展，多媒体信息的安全及版权问题引起了人们越来越多的关注，数字水印技术应运而生，他通过向多媒体数据内隐藏版权信息来保护版权。首先，采用了一种新的基于队列变换的图像置乱技术，提高了水印抗剪切能力，并提供密钥增加了系统的安全性；其次，提出了一种新的基于小波域的盲水印算法，利用小波变换后的系数序列与给定序列之间的相关性来判断提取水印，提取无需原图像，是一种有效的盲水印算法。     

线性空间隐藏模型下图像无损水印的仿真实验分析

旨在分析线性空间隐藏模型下图像无损水印的仿真实验,提出线性空间隐藏模型下无损水印算法提出。通过将原始图像载体划分为图像块序列,结合整数小波变换,获取待嵌水印子带。在0/1水印序列下,结合线性空间隐藏模型,在图像小波域中嵌入水印,不仅提高了水印的鲁棒性,同时也提高了水印的不可见性。结合简单逆向平移的过程,对原始图像进行恢复。对于线性空间隐藏模型,不仅实验了水印的独立性,同时基于无损水印领域,也提高了水印的鲁棒性,并降低误检率,实现原始图像的无损恢复。线性空间隐藏模型下图像无损水印的仿真实验结果表明,算法的应用不仅可以避免有损压缩,同时也有较好的不可见性和安全性。     

基于视觉特性和小波分解的数字水印隐藏方法

本文提出了一种隐藏数字水印的新方法,该方法所隐藏的不是传统的序列码或比特流,而是将水印作为一幅二值图像来处理;并结合人眼视觉模型（ＨＶＳ）和图像的ＤＷＴ多尺度分解来隐藏水印。实验表明这种新方法在降低原始图像变换后视觉失真和提取的被隐藏水印图像失真两方面都达到较好的效果,鲁棒性也较好,这是一种很有发展前景的数字水印隐藏新方法。     

一种改进的基于DWT的二值图像水印算法

文章介绍了数字水印和信息隐藏的相关概念,提出了一种改进的基于离散小波变换的二值图像盲水印算法.首先利用置乱技术将包含隐藏信息的二值水印图像打乱,然后利用改进的基于离散小波变换的嵌入和提取算法实现盲水印.由于文章中提出的算法可以降低对宿主图像的改动幅度,因而具有良好的不可见性和鲁棒性.     

基于DWT和BEMD的图像水印嵌入算法

信息隐藏是信息安全的一个新的重要内容,数字水印技术是信息隐藏技术研究领域的重要分支.鲁棒性和隐藏性是数字水印技术的关键.本文提出了一种基于离散小波变换和二维经验模式分解的图像数字水印算法,在嵌入水印前把水印进行Arnold变换,把水印信息置乱,消除像素的空间相关性,从而提高了水印信息的安全性和鲁棒性.实验结果表明,该水...     

几种图像数据隐藏方法的比较研究

近年来,图像数据隐藏技术得到了突飞猛进的发展,得到了很多鼓舞人心的成果。在图像隐藏技术中,使用最多的图像嵌入规则有三种:加法嵌入规则、乘法嵌入规则以及基于融合技术的图像嵌入规则。本文对这三种图像嵌入规则的性能进行了分析和研究,通过比较我们发现,如果将图像隐藏过程看作是一个水印信道模型,则基于融合技术的图像嵌入规则所能隐藏的信息量远远高于另两种嵌入规则,而乘法嵌入规则其水印信道容量不受原始图像DCT系数标准差变化的影响,因此,在原始图像DCT系数标准差不稳定的情况下,采用乘法嵌入规则是一个好的选择。     

Oriented modulation for watermarking in direct binary search halftone images

In this paper, a halftoning-based watermarking method is presented. This method enables high pixel-depth watermark embedding, while maintaining high image quality. This technique is capable of embedding watermarks with pixel depths up to 3 bits without causing prominent degradation to the image quality. To achieve high image quality, the parallel oriented high-efficient direct binary search (DBS) halftoning is selected to be integrated with the proposed orientation modulation (OM) method. The OM method utilizes different halftone texture orientations to carry different watermark data. In the decoder, the least-mean-square-trained filters are applied for feature extraction from watermarked images in the frequency domain, and the na?ve Bayes classifier is used to analyze the extracted features and ultimately to decode the watermark data. Experimental results show that the DBS-based OM encoding method maintains a high degree of image quality and realizes the processing efficiency and robustness to be adapted in printing applications.     

Multicarrier spread spectrum watermarking for secure error concealment in fading channel

This paper proposes a novel multicarrier spread spectrum (SS) watermarking scheme for the application of image error concealment using multicarrier-code division multiple access (MC-CDMA) with binary phase shift keying (BPSK) transmission in Rayleigh fading channel. The goal is achieved by embedding important information (image digest) which is extracted from the original image itself, and is used to introduce sufficient redundancy in the transmitted image. Half-toning technique is applied to obtain image digest from its low-resolution version. At the decoder side, data demodulation as well as watermark decoding are done using minimum mean square error combining (MMSEC) strategy. The extracted image digest is used to correct the damaged regions. The integration of SS watermarking with the existing SS modulation not only simplifies the design but also offers significant performance improvement for error concealment in fading channel. Authorized users having the knowledge of code patterns for SS watermarking can only perform the error concealment operation and the method is secured. Experimental results duly support the effectiveness of the proposed scheme.     

A new facet in robust digital watermarking framework

Generally, in watermarking techniques the size of the watermark is very small when compared to the host image. On the contrary, this is an attempt in which a new facet in watermarking framework is presented where the size of host image is very small when compared to the watermark image. The core idea of the proposed technique is to first scale up the size of host image equal to the size of watermark using chaotic map and Hessenberg decomposition followed by the redundant wavelet transform. A meaningful gray scale watermark is embedded in the low frequency sub-band at the finest level using singular value decomposition. To prevent ambiguity and enhance the security, a binary watermark is also embedded in loss-less manner which ensures the authenticity of the watermarked image. Finally, a reliable watermark extraction scheme is developed for extracting both the watermarks. The experimental results demonstrate better visual imperceptibility and resiliency of the proposed scheme against intentional or un-intentional variety of attacks.     

一种用于版权通知和保护的 多功能彩色图像水印算法

本文提出一种用于版权通知和保护的多功能彩色图像水印算法.其基本思想是在彩色图像的不同区域分别嵌入可见水印和不可见水印.根据归一化块方差特性在空域中自适应地嵌入可见水印,以实现版权通知功能.利用抖动调制技术在离散余弦变换域(DCT)中嵌入可盲抽取的不可见水印,以实现版权保护功能.实验结果表明,嵌入的可见水印很难去除,不可见水印对彩色图像的质量影响很小,并对常规处理具有较好的鲁棒性.     

Image error concealment and quality access control based on data hiding and cryptography

This paper proposes a data hiding scheme that integrates the dual purpose of error concealment and quality access control of digital image(s) in a single platform. The objective is achieved through the extraction of some important information from the original image itself followed by embedding the same in the host data as watermark which in turn increases sufficient redundancy in the transmitted image. The data embedding is done by modulating integer wavelet coefficients using quantization index modulation (QIM). The watermarked integer wavelet coefficients are then encoded using convolution coding at high code rate. Before data embedding, the important information (watermark) is also encoded with convolution coding and is encrypted using chaotic logistic mapping. The necessary information in the form of the secret key (K) is further encrypted using a public key (P) cryptology for its secret transmission to the receiver. The user who has the knowledge of the secret key (K) can decrypt the hidden information for the concealment purpose, while the users having different partial knowledge of the key (K) enjoy relative qualities of the images by partial recovery of the damaged regions. The simulation results have shown the validity of the claim. The performance of the proposed scheme is also tested in Rayleigh-fading wireless channel and compared with the few other methods.     

Perceptual audio data concealment and watermarking scheme using direct frequency domain substitution

A method is described for perceptually transparent data concealment and watermarking in audio. The proposed system replaces redundant and imperceptible frequency components with hidden data. A psychoacoustic model is used to identify suitable frequency locations for data hiding. Such a method is complicated by the windowing and overlapping requirements used for signal conditioning. The proposed system uses data flipping in place of windowing and incorporates a novel data detection scheme with adaptive weighting to increase the robustness of the watermark transmission. The resistance of the watermarking system to filtering, amplitude scaling and additive white noise is measured and results presented.     

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.     

一种基于DWT的同步数字音频水印算法

本文提出了一种基于离散小波变换的同步数字音频盲水印算法。嵌入的水印为视觉上可辨的二值图像。算法中引入了嵌入同步信号的思想,利用同步信号定位水印的嵌入位置。为了提高信号的鲁棒性,把同步信号与水印隐藏在DWT域的低频系数中。同时,检测水印时不需要原始音频。仿真实验表明,所提出的方法具有较强的鲁棒性和不可感知性,并能有效抵御各种常见攻击。     

基于DWT的同步数字音频盲水印算法研究

文中提出了一种基于离散小波变换的同步数字音频盲水印算法．嵌入的水印为视觉上可辨的二值图像．算法中引入了嵌入同步信号的思想，利用同步信号定位水印的嵌入位置，为了提高信号的鲁棒性，把同步信号与水印隐藏在DWT域的低频系数中；同时，检测水印时不需要原始音频．仿真实验表明：所提出的方法具有较强的鲁棒性和不可感知性，并能有效抵御各种常见攻击．     

谐波小波在TDLAS 信号分析中的应用

波长调制谱技术（WMS）在慢扫描信号基础上叠加上高频的调制电流,并加到半导体激光器的驱动电流上,于是激光频率在线性扫描的同时受交流调制。频率调制的激光束在通过吸收气体以后,其吸收线的强度也受到相同频率调制。采用谐波小波方法作为数据解调的手段,对WMS技术产生的信号进行处理并实现了2f信号的提取。采用这种方法对波数为7185.6 cm-1的水蒸气谱线进行测量实验,调制频率达到180kHz,对数据进行谐波小波处理后获得了高质量的2f信号,该2f 信号的峰值中心辨识度高,其数据光滑度、信号的抗干扰能力方面均优于数字锁相方法。