Quantitative steganalysis of JPEG additive steganography based on boundary effect

Abstract

For quantitative steganalysis of random additive steganography in JPEG DCT domain, an effective embedding ratio estimation method is proposed. First, the modification of coefficients after steganography is regarded as adding additive noise to coefficients. At the same time, variance of pixel differences on the boundary of spatial blocks is used to describe the boundary effect caused by coefficients changing. Then, the functional relationship between coefficient changing rate and boundary effect before and after embedding is presented by theoretical analysis. On the basis of that, the embedding ratio estimation equations are constructed for JPEG additive steganography. Specific forms of the estimation equations are different for various types of steganographies. Finally, for two types of typical DCT domain steganography JSteg and MB1, the corresponding embedding ratio estimation algorithms are presented. Experimental results show that the proposed embedding ratio estimation method based on boundary effect is effective for random additive steganography in JPEG DCT domain.