Steganalysis of PQ Based on the Histogram Difference between Coefficient Adjacent Positions

Steganalysis of PQ (Perturbed Quantization) steganography is a hot but intractable topic in information hiding detection. In this paper, a new steganalysis method of PQ is proposed. Based on the analysis of the embedding position selection mechanism used in PQ, the 63 AC (Alternating Current) coefficient positions of DCT block can be divided into two types: PT1 (Position Type 1, the positions may be used for embedding) and PT2 (Position Type 2, the positions will not be used for embedding). Two coefficient positions which belong to different types and adjacent in the horizontal or vertical direction are considered as a position pair, the histogram difference in each position pair will be changed after embedding, and it is extracted as features. The experimental results verify the effectiveness of the proposed method. Meanwhile, the multi-class combined features provide a more reliable result.