共查询到20条相似文献，搜索用时 15 毫秒
1.
目前大多数压缩域数字视频水印算法都在视频信息的I帧嵌入信息,没有充分挖掘P、B帧的容量.本文通过分析运动矢量的数据统计特性,提出一种基于运动矢量相位统计特性来隐藏水印信息的视频水印算法.该算法最大特点是利用运动矢量相角角度抖动的基本思想将水印信息嵌入到运动矢量中.算法简单、实用.同时利用矩阵编码来解决运动矢量修改率有可能过高问题.实验表明通过该算法具有很好的鲁棒性和不可感知性,能够抵抗帧删除等同步攻击以及基于视频内容的攻击. 相似文献
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提出了一种新的基于视频压缩编码的动态图像水印方案。在嵌入水印时,充分考虑动态图像压缩编码的特性,对帧内编码帧(I帧),将水印信息嵌入到DCT低频系数中;而对帧间编码帧(P,B帧),结合动态补偿/离散余弦变换(MC/DCT)混介编码,把水印信息嵌入到运动补偿后的残差图像的自流成分中。同时,在水印嵌入时,采用扩频技术与多维水印相结合的方法,并通过相关检测的方法判断水印的存在。由于水印的检测是对视频码流直接实施的,不需要对压缩数据进行完全解码,从而大大降低了计算量,提高了视频数据水印的适用性。 相似文献
3.
利用MPEG-2标准的压缩及视频流的特点,讨论了基于DCT变换帧内编码的水印嵌入方法,并提出一种改进的算法.实验证明,该算法改善了压缩视频中水印的嵌入性能. 相似文献
4.
针对MPEG-2标准,提出一种新的盲水印算法,首先使用领域平均的方法,计算载体视频两条I帧DCT变换低频系数均线的交叉点作为嵌入位置,然后利用奇偶量化的方法实现水印信息与同步码的嵌入。实验表明,算法具有较好的不可见性,且针对常规攻击具有较强的鲁棒性。 相似文献
5.
根据MPEG-2压缩视频的原理,提出了一种基于DCT域的MPEG-2视频水印技术的设计方法。该算法将水印信息经Arnold置乱后嵌入到视频I帧的色度DCT中频系数中,并且充分考虑了人眼的视觉特征。新算法易于实现,具有较高的鲁棒性。 相似文献
6.
研究一种针对H.264编码的帧间预测块划分视频水印算法,该算法先对水印图像进行二值处理,然后在H.264帧间预测编码时根据水印二值序列选择不同的区块划分,并将水印值嵌入进去.实验结果表明,该算法具有较好的实时性、鲁棒性. 相似文献
7.
针对传统视频水印算法鲁棒性和安全性较差的问题,提出了一种新的结合双树复小波变换(DT-CWT)和奇异值分解(SVD)的视频半盲水印方法。算法首先从视频中提取I帧,其数量和位置均由用户决定,具有良好的保密性。I帧的亮度分量经DT-CWT变换的系数有较强的鲁棒性、更佳的重构效果、灵活的水印嵌入位置以及更多的方向选择性,SVD分解后的奇异值具有良好的抗几何失真不变性。同时还生成了一个随机密钥,有效提高了视频水印的安全性。实验结果表明,该算法对视频质量的影响较小,并且能有效抵御高斯噪声、椒盐噪声、JPEG压缩、直方图均衡化、帧交换、帧删除及帧平均等多种攻击,具有较强的鲁棒性。 相似文献
8.
吴晓明 《思茅师范高等专科学校学报》2015,(3):50-52
数学教学中把理论转化为实践是非常有意义的,算法是一个很好的实现途径。通过改进了一种水印算法,具体做法是全部利用彩色图像各原色图像帧的 DCT 系数,把非盲水印嵌入其中,在保证水印嵌入后图像质量不受影响的基础上,使嵌入的信息量加大,以提高水印的抗攻击性,进而实现版权保护的应用目的。 相似文献
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鲁晓辉 《洛阳工业高等专科学校学报》2015,(2)
针对数字视频版权保护问题,利用人类视觉系统（HVS）特性基于 MPEG －2标准提出一种盲水印算法。首先选定为 B 帧亮度最高的3个8×8 DCT 分块作为水印嵌入位置,然后利用分块位置和低频分量增长趋势实现水印的嵌入,最后通过仿真实验验证了算法的不可见性与鲁棒性。 相似文献
10.
为了使数字水印实现多种功能,提出了一种能在同一音频信号中同时嵌入多个水印的新方法.首先,载体音频信号被分隔成指定长度的帧,并且所有成员水印被编码成一个混合水印.然后,利用回声隐藏技术将混合水印中的二进制比特嵌入到音频信号帧中.水印提取不需要原始音频信号.为了提高水印算法的提取正确率和抵御常规信号处理的鲁棒性,功率倒谱的自相关被用于检测携带水印的音频信号帧中的回声延时以提取出混合水印,并且相应的解码算法被用于分离成员水印.计算机仿真结果表明所提出的水印算法对常规的信号处理,如Mp3压缩、重采样、重量化、低通滤波以及白噪声具有很强的鲁棒性. 相似文献
11.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
12.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
13.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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15.
陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
16.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
17.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
19.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
20.
Anton Franks 《English in Education》1999,33(2):39-49
This paper looks at the way drama works to bring a model of an arts curriculum into reality. He also shows how drama is valuable when discussed as a separate, autonomous subject in the school curriculum as opposed to one subsumed within English. He argues for a view of the arts and gives an example of a sequence of work in an English GCSE class based around Arthur Miller's play View from the Bridge. From this he draws out several strands about the relationship of the drama curriculum to the individual students and teachers, the school, and to culture. He also emphasises the primacy of performance in drama education. 相似文献