查询词典 watermark

The watermark data are embedded into some proper hypercomplex frequency components and their corresponding HFT coefficients are modified to fulfill the symmetry constraint. The prerequisite, the watermarked host image in spatial domain should also be transferred in red, green, and blue channels, of embedding watermark data into the hypercomplex frequency domain is obtained.

它通过对彩色载体图像进行快速超复数傅氏变换，在超复数频域选择合适频段嵌入水印，并且修改其对称系数的值，保证了嵌入水印图像仍然可以用彩色图像的红、绿、蓝三色进行传输。

Then, it introduces an adaptive blind watermark algorithm based on odd-even judgement. This algorithm uses the neighboring symbols mean value and the odd-even judgement to embed the watermark into the 2-level subband of the carrier image. The results of the test demonstrate that this algorithm has a good imperceptivity and robustness.

然后，在此基础上介绍了一种基于奇偶判决的图像自适应盲水印算法，该算法利用图像小波系数的相邻特征平均值和奇偶判决法在图像小波域的二阶子带上嵌入水印，试验结果表明该方法具有不错的不可见性和鲁棒性。

In every period, do the following operations:# For each 8*8 block, do the discrete cosine transform, then take out direct current coefficient in each block, using the transformation above for each DC coefficient, the gold stands for the code of the spread-spectrum we use when embedding the different watermark bit in different frames, after all of the watermark information which we want to embed is embedded, then do the inverse discrete cosine transformation, and store the current frame in a new file.

于是利用DCT变换域的这点重要的几何不变性，我们可以推导出一种能够抵抗几何攻击的视频水印算法，即将所需要嵌入的水印信息以127位扩频序列作为辅助，以求和值形式嵌入到DCT变换后的每个宏块的每个DC系数当中，具体嵌入和提取算法如下：根据使用的扩频序列的长度N，基于相关的嵌入器需要选取包含N帧的视频子序列，令这N帧视频子序列作为一个嵌入周期，对于每N帧视频子序列做如下的操作，#即对于每个8×8的像素块进行DCT变换，然后取出每个DCT变换后的直流分量，对于每个DC系数，做如上所述的变换，其中gold为在第k帧中嵌入第i位水印信息时使用的扩频码字值，待将所有需要嵌入的水印信息全部嵌入后，再做反DCT变换，保存当前帧。

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。

First determined the lower limit and the upper limit of picture element value is 1, then to the recovered watermark image has carried on two values processing, caused the final watermark image effect to be better.

首先确定像素值为1的下限和上限，然后对提取的水印图像进行了二值化处理，使最终的水印图像效果更佳。

On the research of robustness of watermark there are three aspects: first, we analyze the influence of low-pass filter to digital watermark.

对鲁棒水印技术问题的研究，包括以下三方面：首先，分析了低通滤波对数字水印鲁棒性的影响。

Watermark casting operates in frequency domain,embeds pseudo random sequence of real number in selected coefficients without image degradation To insert the watermark image and the original image from the original look and value and the picture basically the same.

本文主要研究针对图像水印系统的算法研究，采用离散余弦的实现方式对图片进行水印的处理，让插入水印后的图片和原来的图片从外观和价值和原来的图片基本一致。

The robustness of watermark is vital to the practical application , which requires the watermark providing with significant data since it suffered from some intended attacks or unintended revisal

水印算法的鲁棒性对于实际应用来说是至关重要的，它要求数字水印在遭受有意的攻击或无意的修改后，仍能提供有意义的数据，这一性能对版权保护的应用显得尤为突出。

Applied DWT to R,G,B channel correspondingly, and used three low frequent coefficients to construct a 3-level tensor. Embedding the watermark into the core tensor, which got form Tucker decomposition, could diffuse the watermark into R,G,B.

首先对彩色图像R、G、B三通道进行小波变换，然后将获得的三个低频系数构成三阶张量，再经过Tucker分解后获得核心张量，通过在核心张量中嵌入水印信息使得水印信息扩散到原彩色图像的R、G、B三个分量中。

In Chapter 2, a detailed survey on digital image watermarking is presented. InChapter 3, an optimal scheme is proposed to use Human Visual System model tocompute masking function. It will be used to control the strength of watermark signalfor optimal embedding. In Chapter 4, we propose a novel watermarking scheme based on lattice vectorquantization. Some important transform coefficients of the original image are firstlymapped into the nearest neighboring lattice points by using lattice vector quantizer,then watermark signal is added to the lattice points.

本文讨论了数字图像水印及其在多媒体安全中的应用，主要围绕下列问题进行研究和创新：1、优化的水印嵌入模型：本文对基于直接序列扩频技术的水印算法进行了改进，根据人类视觉系统感知模型，提出了优化的水印嵌入模型，在不可感知性条件的限制下，使水印的鲁棒性达到最高。2、基于格矢量量化的图像水印：本文提出了基于格矢量量化的多比特盲水印算法，不需要原始图象就可以实现水印信号的检测和译码。

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。