水印

Then the digital audio signal is set into segments and DWT is performed. Finally the modulated signal is embedded in the coefficients with relatively large absolute value on middle frequency range detail signal adaptively. The original digital audio signal is necessary when detecting the watermark.

在应用扩频技术的算法中，首先将视觉上可辨的二值水印图像降维为一维序列，再将一维水印序列伪随机排序并与m序列作扩频调制，最后对数字音频信号进行分段离散小波变换，把经过调制的水印信息自适应地嵌入到原音频信号小波分解中等尺度绝对值较大的分量上。

The method includes steps: digital watermark technique is adopted to hide information of key data in not key data codes of compressed image; under protection of digital watermark, using protective backup for key data detects whether normal transmitted key data is correct or not so as to detect error code; carrying out cyclic mutual backup by using macro blocks in same positions in front and back macro block set; embedding coded motion vector in form of digital watermark to DCT transformation coefficient, and ensuring that video data are not influenced as best as one can; when error code occurs, if key data backup is correct, then the backup replaces former key data; otherwise, using mean value of key data in adjacent macro blocks within same frame to replace former key data approximately.

本发明中，采用数字水印技术在压缩图像的非关键数据编码中隐藏关键数据信息；通过数字水印保护下的关键数据保护备份来检测正常传输的关键数据是否正确，由此来检测传输误码；用前后宏块组中相同位置的宏块进行循环相互备份；对运动向量进行编码，然后以数字水印的形式嵌入到相对不重要的DCT变换系数中，同时保证视频数据尽量不受影响；在误码发生时，如果关键数据备份正确，则直接替代原关键数据，否则用同一帧内相邻宏块的关键数据的平均值近似替代原关键数据。

Since only a subset of counter watermark detection techniques is selected from a larger pool of techniques, a bootlegger will be unaware of the total number of transformations available to the watermark detectors and will therefore not know if the watermark has been successfully removed or corrupted.

由于仅从技术的较大集合中选择反水印检测技术的子集，因此非法贩卖者将不知道水印检测器可用的变换的总数，从而将不知道水印是否已被成功除去或破坏。

Based on summarizing modern watermarking techniques, the appearance, application, Watermark system principle, classifications and attacks are outlined in this paper. According to the fundamental principles of the information theory, and digital image processing, and chromatology, this thesis studies the theory and applications of the color image watermarking processing.

由于大多数现有技术考虑灰度图像、无意义水印，根据信息隐藏与数字水印技术、数字图像处理和色彩论的基本原理，本文主要研究了彩色图像的有意义水印的处理。

In the discrete wavelet transform domain, the watermark sequence is modulated with m-sequence at first, then the watermark information is embedded by quantifying the coefficient of the transform domain. The quantification procession is given.

4在离散小波变换域，先对水印序列进行扩频调制，然后通过对变换域系数进行量化来嵌入水印信息，给出了量化方案；在水印的提取过程中不需要原始音频信号的参与。

And watermark image is embedded by the rule of the improved binary operation, changing wavelet coefficients part of the decimal to improve the quality of the image after the watermark embedded.

水印嵌入采用改进的二值运算方法，通过修改小波系数的小数部分来实现水印的嵌入，提高了水印嵌入后图像的视觉质量。

The following question of multi-scheme and multi-watermark is mutual conflicts between district watermarkings. How to deal with the conflicts, and to analyze and stretch the capacity of the multiply data hiding technologies is the unignored problem for the research on copyright protection of MPEG-4 Audio.

多水印的应用必然会存在相互之间的矛盾冲突以及对传统的单水印模式的冲击，如何利用网络信息论、通讯理论等建立合理的多水印模型来控制相互之间的矛盾冲突、优化水印嵌入和检测算法是MPEG-4音频版权保护不容忽视的关键问题。

According to the ability of identifying tampers, fragile watermark can be divided into two classes: complete fragile watermark and semi-fragile watermark.

根据水印识别篡改的能力可以将脆弱水印分为完全脆弱水印和半脆弱水印。

Firstly, the proposed metric acquires the watermark embedded map based on the characteristics of human visual system. Then, the 3-level discrete wavelet decomposition is implemented, and the digital watermark is embedded into each wavelet coefficient block according to the watermark embedded map.

提出的方法首先结合人类视觉系统的特性检测原始图像的纹理丰富区域，获得水印嵌入指示图；然后将原始图像进行3层小波分解，根据水印嵌入指示图在每个小波系数块内利用量化的方法嵌入自定义水印；最后通过失真图像的水印复原率实现对图像的客观质量评价。

The BCH coded authentication data is modulated by chaotic sequence and then embedded into the DCT domain of the image by using the owner's private key.The embedding process is controlled by Just Noticeable Difference of the DCT block.Users can extract the authentication data with the public key,while they can't get the private key to destroy or delete the watermark through the public key.

提出一种基于非对称水印的图像认证改进算法，算法中将经过BCH编码和混沌序列调制的认证信息作为水印，利用所有者私钥嵌入图像DCT域，嵌入过程根据DCT块的可视噪声阈值控制，用户可以利用公钥从水印图像中提取认证信息，但无法从公钥中获取任何私钥信息，从而无法破坏或删除水印。

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。