水印

Firstly, chaotic kinetic characteristic of Kent mapping is analyzed, using it to encrypt watermark image; Secondly, an algorithm of only modifying the decimal part of DC components is given, bringing the least error, effectively solving the problem which embedding watermark in DC components is easy to the image's block effect; Watermark is extracted without original image utilizing two-bits algorithm.

深入分析了帐篷映射的混沌动力学特性，并将其应用于水印图像的预处理；在分析了 DCT域嵌入对策的基础上提出了一种只修改 DC 分量小数部分的嵌入算法，引入的误差小，有效的解决了以往人们在 DC 分量嵌入水印容易引起图像块效应的问题；检测过程中利用二值离散算法使得水印提取时无需原始图像。

Basic knowledge of digital watermarking such as background, fundamental theory, characteristics, algorithm evaluating is introduced in this thesis.

本文简介了数字水印背景、基本原理、特征、算法评测等基本知识，介绍了目前主流数字水印算法，给出了DCT域和DWT域两种数字盲水印算法。

Afterward make each watermark pixel hide in corresponding image block's mid-low frequency wavelet modulus, improve the concealment and haleness of watermark..

同时，为了使水印分布在整个图像，对加密的水印序列再进行置乱处理，提高了数字水印的稳健性和抗攻击性。

Finally, haven the experiment in MATLAB about imbedding watermarking, detecting watermarking and cutting attacks.

最后，在MATLAB中对水印的嵌入、水印的检测与水印的剪切攻击进行了实验。

This finished the embedding process, and the test results show that this algorithm has certain imperceptivity and robustness. Because of the same embedding intensity, on one hand, it leads to the decline of the quality of the carrier image and influence the transparency and robustness of the watermark.

在此基础上，本文介绍了一种传统的基于小波变换的数字水印算法，这种算法将数字水印小波分解后的各个子带，嵌入到原始载体图像第三级小波子带中去，实现了水印的嵌入，试验结果显示该算法具有一定的不可见性和鲁棒性。

Experimental results show that the two schemes can preserve inaudibility and they are robust enough to against the different signal processing operations. In addition, very large watermarking information can be embedded into the original audio signal. Furthermore, it can resist the cropping and MP3 compression attacks.

仿真实验结果表明，两种算法都具有较强的鲁棒性和不可感知性，水印嵌入容量大，提取水印时不需要原始音频信号的参与，并且对裁剪、时间伸缩等攻击具有较强的稳健性，是可行的数字音频水印算法。

So, a novel machine learning based digital blind audio watermarking scheme in the wavelet domain is proposed in this paper, which could find a reasonable balance between the robustness and inaudibility of the watermark, then have the better robustness and inaudibility.

本文正是将小波变换应用到音频信号的数字水印系统中，提出一种小波域上基于机器学习方法的新的数字音频盲水印算法，使其能在水印的鲁棒性和不可感知性之间寻找到合理的平衡点，从而具有更良好透明性和鲁棒性，并在音频作品的版权保护中能有一定的实用性。

The experimental results show the two practical algorithms can preserve inaudibility and they are robust enough to against the different signal processing operations. In addition, the watermarking information can be embedded into the original audio signal adaptively, which also doesnt require the use of the original audio signal for detection. Furthermore, it can resist the different attacks, such as lossy compression (MP3), filtering, resampling and requantizing, etc.

仿真实验结果表明，两种方法都具有较强的鲁棒性和不可感知性，水印嵌入容量的自适应性，提取水印时不需要原始音频信号的参与，且对包括MP3有损压缩、低通滤波、重采样/重量化等多种攻击性试验具有较强的稳健性，是可行的数字音频水印算法。

Currently familiar formulas called normalized correlation, which are used for evaluating the similarity degree of digital watermarks, showed their big shortage when expressing the similarity degree of extracted watermark and original watermark in inverse similarity.

摘要当前常见的作为评价数字水印相似程度公式的归一化相关值，在表示提取出的水印与原始水印反面相似时存在很大的不足。

Inthe paper, the blind inspection is executed by using modular arithmetic, namely, modulus 2arithmetic.(The result is 0 or 1). A algorithm with high transparency and robustness is realizedby smartly combining this arithmetic with binary chaotic sequence.

文中利用模数运算实现了音频水印的盲检测，即利用模2 运算，模2 取余(所得结果为0 或1)，很巧妙地将这种运算与二值化的混沌水印序列相结合，实现了一种不可感知度高，嵌入量大的高鲁棒性水印算法。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。