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不确定性推理一直是人工智能研究的重点,基于此首先阐述了不确定性推理规则的组成及其含义,然后提出了不确定性推理的通用模型,给出了一种基于可信度区间的推理方法,通过引入可信度区间、区间匹配函数来进行不确定性推理,在推理结果中通过引入权重系数来进行区间排序,从而衡量各个结果,使得推理结果更加接近实际情况。通过实例算法验证,该方法简单有效。 相似文献
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设计高性能嵌入算法与选择合适载体图像是提高隐写术性能的两个重要途径.基于像素差值PVD(pixel-value differencing)是一种算法复杂度低,嵌入容量大的高性能隐写算法.本文针对PVD嵌入算法,研究最佳载体选择问题.论文分析与讨论载体图像的复杂度、直方图及其平滑度等载体图像特征值,和相对熵、直方图的改变量等隐写术系统性能参数之间的关系,研究载体图像的特征值对PVD隐写术系统性能的影响,为PVD隐写算法选择最佳的载体图像提供理论依据.实验结果表明,选择直方图曲线连续变化缓慢的图像作为PVD隐写算法的载体图像,能有效提高隐写术系统的不可感知性能. 相似文献
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本文首先总结了当前的LSB隐写检测算法,特别是RS检测算法及其改进算法.对其进行数学建模,得到LSB嵌入方法的通用数学模型.通过LSB嵌入法的模型,提出一个基于多进制嵌入的数学模型及其算法.多进制算法具有嵌入信息量大,同时能够抵抗经典的RS检测算法. 相似文献
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基于图像的广义隐写分析 总被引:1,自引:1,他引:0
主要对基于图像的广义隐写分析算法进行了研究,选取4种对信息隐藏分析效果最好的图像质量度量标准(Image Quality Metrics),运用误差反传(Back Promulgate)神经网络设计了一套广义隐写分析系统,并将其用于最终隐写图像的检测分类上.经实验证明,该方法具有较高的准确率和普遍的适应性,因而可用于实际的隐写图像检测分析中. 相似文献
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针对现有的基于特征融合的JPEG隐写分析方法特征冗余度高、通用性较低的问题,提出了一种基于改进的增强特征选择(BFS,boosting feature selection)算法的通用JPEG隐写分析方法。从线性相关度和非线性相关度两方面降低特征冗余,将特征自相关系数和互信息这两种统计性能引入到特征的评价准则中,重新设计了特征权重计算方法,改进了BFS算法的特征评价函数。通过改进的BFS特征选择算法将3组互补性较强且准确率高的特征进行融合降维,得到最优特征子集训练分类器。对3种高隐蔽性隐写算法F5、Outguess和MME3,在不同嵌入率下进行了大量实验。结果表明,本文方法的分析准确率高于现有的检测率较高的JPEG隐写分析方法和典型的融合分析方法,融合后的特征相关性明显下降,并且具有更强的通用性。 相似文献
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空域LSB信息伪装的隐写分析及其对策 总被引:14,自引:0,他引:14
回顾了几种针对空域LSB信息伪装的隐写分析方法,包括直方图攻击,RS分析方法和几种通用盲检测方法,同时指出只需要对传统LSB替换方法作很小的改动就可以避开前两种攻击方法,完善了矩阵编码方法,提出了基于分组码理论构造高效信息伪装编码的完整方案,指出采用高效编码方案可以大大降低通用盲检测算法的可靠性。 相似文献
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Steganalysis is the art and skill of discriminating stego images from cover images. Image steganalysis algorithms can be divided into two broad categories, specific and universal. In this paper, a novel universal image steganalysis algorithm is proposed which is called RISAB, Region based Image Steganalysis using Artificial Bee colony. The goal of the proposed method is to realize a sub-image from stego and cover images through ABC with respect to density according to the cover, stego and difference images. In our method, we look for the best sub-image, which contains the highest density with respect to the changed embedding pixels. Furthermore, after selecting the best sub-image, we extract the features, which have been selected by IFAB, Image steganalysis based on Feature selection using Artificial Bee colony. At the end, both selected features by IFAB and extracted features by RISAB are combined. As a result, a feature vector is generated which improves accuracy of steganalysis. Experimental results show that our proposed method outperforms other approaches. 相似文献
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基于短重码间距统计的隐写检测方法对LSB匹配等隐写技术有良好的检测性能.然而该方法为适应不同的应用场合,需要选择适当的短重码维数.这种一元统计分析方法无法考虑多个特征之间存在的联系,从而影响检测能力.本文分析证明了单个短重码间距统计变量的检测能力规律,给出了可减少检测次数的合理选择短重码维数的方法.基于短重码间距统计特征变量之间的相关性选择特征子集,构造局部特征描述向量,进而提出一种基于LSB序列局部特征的通用隐写检测方法.该方法采用GMM生成模型描述多维局部特征,并基于全局序列词汇设计融合GMM生成模型与SVM判别方法的分类器.实验结果表明:本文方法在有效控制虚警率的前提下,对LSB匹配隐写和LSB替换隐写都有较好的检测性能. 相似文献
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Steganalysis attack is to statistically estimate the embedded watermark in the watermarked multimedia,and the estimated watermark may be destroyed by the attacker.The existing methods of false negative probability,however,do not consider the influence of steganalysis attack.This paper proposed the game theory based false negative probability to estimate the impacts of steganalysis attack,as well as unintentional attack.Specifically,game theory was used to model the collision between the embedment and steganalysis attack,and derive the optimal building embedding/attacking strategy.Such optimal playing strategies devote to calculating the attacker destructed watermark,used for calculation of the game theory based false negative probability.The experimental results show that watermark detection reliability measured using our proposed method,in comparison,can better reflect the real scenario in which the embedded watermark undergoes unintentional attack and the attacker using steganalysis attack.This paper provides a foundation for investigating countermeasures of digital watermarking community against steganalysis attack. 相似文献
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针对无向通信网的节点和链路都存在失效的问题,提出了端到端可靠性的通用算法。对无向网络基于概率论的分解定理进行证明,介绍了无向网络的简化与分解算法及流程,并分析了端到端可靠度的计算准则,针对3种复杂程度无向网络进行了分析比较,最后提出一种无向通信网端对端可靠性通用算法。分析结果表明提出的通用算法适合节点和链路都不可靠的情... 相似文献
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论文分别从空间域、变换域分析了常用的图像信息隐藏和检测技术,研究了一种可对DFT域、DCT域和DWT域图像信息隐藏实现通用盲检测的、基于频率域差分直方图能量分布分析的检测方法,设计了互联网内容监管网关中的图像信息隐藏检测模块,并通过功能性实验证明了其有效性。 相似文献
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In reliability engineering, there always exist uncertainties caused by the scarcity of data and information. Various metrics are developed to measure reliability under uncertainty, including evidence-theory-based reliability, interval-analysis-based reliability, fuzzy-interval-analysis-based reliability, posbist reliability and belief reliability. As these five metrics are difficult to be fully understood, it is hard to select the most appropriate one for a specific condition. This paper will propose an uncertain evaluating model to conduct an objective evaluation on these uncertainty metrics. An evaluating index system is established from the aspects of capabilities and adaptabilities. Uncertainty theory is adopted to deal with subjective uncertainties in the quantification process of the index system. Then an evaluating method based on uncertain data envelopment analysis is proposed to provide decision-makers with a succinct result for a given operational context. Finally, the evaluating method is illustrated with a numerical example, which shows that final metric choices vary with different requirements. 相似文献
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