基于图像平滑度的空域LSB嵌入的检测算法

Detection Algorithm for Spatial LSB Embedding Based on Image Smoothness

对图像像素值与邻域均值的差的分布进行建模,以该分布的方差定义了图像平滑度的概念,进而通过对消息嵌入、LSB平面取反带来的图像平滑度的变化进行分析,提出了针对空域LSB替换伪装算法的秘密消息长度估计算法,该算法可以准确地估计图像中嵌入的秘密信息数据量的大小.文中算法物理意义直观、实现简单、计算量小、计算速度快,有利于实现实时检测.实验结果表明该方法是有效的.

A new steganalytic technique capable of reliable detection of spatial LSB steganography is proposed. First, the distribution of the difference between the current pixel and its neighborhood average is statistically modeled, and then the variance of this distribution is defined as the image smoothness. Based on the analysis of the effects on the image smoothness brought by message embedding and LSB plane flipping, an estimation of the secret message length is derived. The algorithm can accurately estimate the amount of hidden messages and detect the existence of hidden messages embedded in the image simultaneously. It has also a distinct physical meaning, and is easy to implement, computationally efficient, and is more suitable for real-time detection. Experimental results show that the proposed algorithm is effective.