论文标题
jpeg的模拟和DCT系数的同步给定开发管道
JPEG Steganography and Synchronization of DCT Coefficients for a Given Development Pipeline
论文作者
论文摘要
这篇简短的论文建议使用DCT系数之间的相关性的统计分析来设计一种新的同步策略，该策略可用于JPEG域中的基于成本的密集术方案。首先，对相邻块的DCT系数的协方差矩阵进行了分析，类似于用于生成BossBase的开发。该分析表明了无关系数的组：每个块和2组无关的对角线邻居以及相互关联的系数组，每个集团6个系数和8个系数在2个相邻块之间，以及8个系数。使用不相关的组，只能使用8个不相交的晶格设计嵌入方案。首先，使用隐式的基础高斯分布，并从嵌入成本直接计算出差异，其次是通过从多元分布中得出条件分布，首先使用隐式基础高斯分布来更新每个晶格的成本图。这些分布的协方差矩阵考虑了协方差矩阵分析所表现出的相关性，又要从成本中得出的差异。这种同步方案使使用DCTR特征集接近0.3 BNZAC系数的嵌入速率在QF 95处获得5％的PE的增益。
This short paper proposes to use the statistical analysis of the correlation between DCT coefficients to design a new synchronization strategy that can be used for cost-based steganographic schemes in the JPEG domain. First, an analysis is performed on the covariance matrix of DCT coefficients of neighboring blocks after a development similar to the one used to generate BossBase. This analysis exhibits groups of uncorrelated coefficients: 4 groups per block and 2 groups of uncorrelated diagonal neighbors together with groups of mutually correlated coefficients groups of 6 coefficients per blocs and 8 coefficients between 2 adjacent blocks. Using the uncorrelated groups, an embedding scheme can be designed using only 8 disjoint lattices. The cost map for each lattice is updated firstly by using an implicit underlying Gaussian distribution with a variance directly computed from the embedding costs, and secondly by deriving conditional distributions from multivariate distributions. The covariance matrix of these distributions takes into account both the correlations exhibited by the analysis of the covariance matrix and the variance derived from the cost. This synchronization scheme enables to obtain a gain of PE of 5% at QF 95 for an embedding rate close to 0.3 bnzac coefficient using DCTR feature sets.
