一类自适应隐写的更改比率估计

Modification ratio estimation for a category of adaptive steganography

针对图像自适应隐写的检测问题,分析了最低多有效位(MLSB,multiple least signific ant bits)替换隐写的样本对分析模型在对自适应隐写的适用性,给出了适于该模型检测的自适应隐写须满足的条件,对满足条件的一类自适应隐写,给出了基于特定区域和像素对分析的定量分析一般方法,然后针对一种典型自适应隐写,给出了具体的特定区域选取方法、样本对跟踪集选取方法和隐写更改比率估计算法.实验结果表明针对这种隐写,该算法能够较为准确地估计隐写更改比率,验证了文中方法的有效性.

This paper investigates the detection of adaptive image steganography.Firstly,the sample pair analysis model of multiple least-significant bits（MLSB） replacement is analyzed,and the conditions under which the adaptive steganography can be detected via this model are given.For the category of adaptive steganography satisfying these conditions,a general quantitative steganalysis method is presented based on specific areas and sample pair analysis.Then,for a typical adaptive steganography,some concrete methods are proposed to select specific areas and trace sets of sample pairs,and estimate the stego modification ratios.Experimental results show that the proposed methods can estimate the stego modification ratio accurately.This verifies the validity of the proposed general quantitative steganalysis method.