一种基于奇异值分解的稳健数字水印算法

提出了一种基于奇异值分解的数字水印算法，它对常见的失真是稳健的。由服从标准正态分布的随机数组成的水印被嵌入到图像分解后的奇异值中。实验结果表明本算法具有很好的稳健性。在经过了一般的信号处理操作和JPEG压缩以后，嵌入的水印能够被可靠地提取和检测。特别地，本算法对转置、行(列)镜像、直角旋转、行(列)整数倍放大和有填充平移等几何失真具有不变性。     

一种小波域内的鲁棒脆弱图像水印技术

目前的水印算法有鲁棒水印和脆弱水印两类,分别可以用于图像的版权保护和篡改检测,但很少有算法能够结合两者,同时实现这两种功能。为了解决这一问题,该文提出一种鲁棒-脆弱水印算法：首先在小波变换图像的逼近子带中,利用系数间的关系构造特征水印;然后根据小波零树思想,结合主分量分析,采用抖动调制方法嵌人到重要小波树的第一主分量中;水印检测时,将提取的特征水印与嵌入水印进行比较,不仅可以确定图像的版权,还可以证明内容的完整性。实验结果表明,此算法能够抵抗滤波、压缩、叠加噪声等处理,同时还可以很好的定位图像的篡改,是一种很有效的水印算法。     

A robust software watermarking for copyright protection

This paper advocates protecting software copyright through hiding watermarks in various data structures used by the code, e.g., B+-trees, R-trees, linked lists, etc. Prior proposals hide the watermarks in dummy data structures, e.g., linked lists and graphs that are created, solely for this reason, during the execution of the hosting software. This makes them vulnerable to subtractive attacks, because the attacker can remove the dummy data structures without altering the functionality or the semantic of the software program. We argue that hiding watermarks in one or more data structures that are used by the program would make the watermark more robust because disturbing the watermark would affect the semantic and the functionality of the underlying software. The challenge is that the insertion of the watermark should have a minimal effect on the operations and performance of the data structure.This paper proposes a novel method for watermarking R-tree data structure and its variants. The proposed watermarking technique does not change the values of the stored data objects. It takes advantage of the redundancy in the order of entries inside the R-tree nodes. Entries are arranged relative to a “secret” initial order, known only to the software owner, using a technique based on a numbering system that uses variable radix with factorial base. The addition of the watermark in the R-tree data structure does not affect the performance nor does it increase the size of the R-tree. The paper provides a detailed security analysis and performance evaluation to show that the embedded watermarks are robust and can withstand various types of attacks.     

基于矢量量化的数字水印综述

基于矢量量化的数字水印作为新出现的水印技术，对数字产品的版权保护起着非常重要的作用。本文对基于矢量量化的数字水印算法做了综述，介绍了现有的各种水印算法，分析了各自的特点，并指出下一步的研究方向。     

Robust multi bit and high quality audio watermarking using pseudo-random sequences

A robust multi bit and high quality audio watermarking technique in time domain is proposed in this paper. Watermarking is a technique used to label digital media by hiding copyright or other information into the underlying data. The watermark must be imperceptible and undetectable by the user and should be robust to various types of distortion. To enhance the robustness and taper-resistance of the embedded watermark, in this paper a multi bit technique is employed. Instead of embedding one bit into an audio frame, multiple bits can be embedded into each audio sub-frame. For attackers, since they do not know the parameters, this significantly reduces the possibility of unauthorized bit detection and removal of watermark. In real-time watermarking applications, robustness is not the only factor that plays an important role. The other factor that plays a very an important role is computational complexity. In general, audio file is transmitted in compressed form. Real-time watermark embedding must take into account this compressed form, because first decompressing the data, adding a watermark and then recompressing the data is computationally too demanding. In this paper, we propose robust and low complexity audio watermarking algorithm. To evaluate the performance of the proposed audio watermarking algorithm, subjective and objective quality tests including bit error rate (BER) and signal-to-noise ratio (SNR) were conducted. Compared to traditional one bit embedding algorithm, the proposed algorithm gives highly recovery rate after attack by commonly used audio data manipulations, such as low pass filtering, requantization, resampling, and MP3 compression.     

A DCT-based ownership identification method with gray-level and colorful signatures

In this paper, we propose an ownership identification method based on discrete cosine transformation (DCT). The copyright owner can select a gray-level or colorful image to be an ownership statement, which is used as a claim to the ownership of his/her work. Unlike traditional watermarking schemes, the ownership statement is not embedded into the image to be protected. Instead, our method will construct an ownership share for the author according to the feature of the original image and the ownership statement. The feature map of the original image is composed of DC coefficients of different DCT blocks. When piracy happens, the author can show his ownership share to reveal the ownership statement to prove his/her copyright. Note that the size of the ownership statement is not restricted to being smaller than that of the host image. In addition, multiple ownership statements can be registered for a single image without destroying each other. The experimental results will show the robustness of our scheme against several common attacks. Finally, we will give some discussions and comparisons with other researchers’ study.     

基于文本文档的版权保护技术研究

为了减少因特网上侵权现象，针对文本文档，描述用来保护文本文档的版权的几种编码方式，这些文档编技术能用来确定文本文档被非法复制后的版权归属和容许执行该非法复制的合法用户。     

彩色数字水印技术研究

本文对彩色水印技术进行了详细地研究，提出了一种双彩色数字水印方案，实验结果表明，该算法性能良好，对于一般的图像处理和JPEG压缩具有较好的鲁棒性。     

数字水印及其应用

数字水印是用信号处理的方法，在数字化的多媒体数据中嵌入的隐蔽标记，本文研究了数字水印的关键技术，探讨了数字水印在版权保护、电子交易，票据防伪等方面的应用，最后展望了数字水印的发展前景。