排序方式: 共有25条查询结果,搜索用时 15 毫秒
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利用双树复小波变换并结合人眼视网膜的颜色特性,提出一种基于融合的彩色图像水印方案。利用复小波变换的平移不变性和多方向性来增强水印受攻击时的鲁棒性。通过试验调整水印能量在蓝、绿、红3种颜色信道里的比例来提高水印的不可见性。结果表明该水印方案在压缩、增加噪声、中值和平均滤波攻击下具有较高的鲁棒性。 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
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《International Journal of Information Management》2016,36(2):192-206
This study provides nascent information on university students' needs to adopt social networking sites (SNSs) pervasively. The study drew from the uses and gratifications theory (UGT) and social influence (SI) processes framework. Relevant hypotheses were formulated to test the proposed research model. Data was collected in a survey of university undergraduates in four countries in the Americas (i.e., United States, Canada, Mexico, and Argentina). Data analysis using partial least squares (PLS) supported 8 out of the 10 hypotheses formulated. The SI process of internalization and identification, as well as UGT categories of self-discovery, entertainment value, social enhancement, and the need to maintain interpersonal connectivity through the construct of behavioral intentions, were found to have positive impacts on students' pervasive adoption of SNSs. The results also revealed that the cultural factor of individualism–collectivism had a positive impact on the pervasive adoption of SNSs, such that greater levels of engagement were observed for students from more individualistic cultures. 相似文献
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Internet和多媒体信息处理技术的迅速发展,给人们带来便利,同时也暴露出日益严重的安全问题。为了解决此类的安全问题,近年信息安全技术研究领域出现了一个新的研究方向一信息隐藏技术,作为版权保护、防止非法复制、图像安全认证、隐蔽通讯以及电子商务中网页保护和票据防伪等方面的有力工具,其中两种技术----数字水印、数字指纹已得到了广泛的应用。 相似文献