Double Compression Detection Based on Markov Model of the First Digits of DCT Coefficients
Double compression usually occurs after the image has gone through some kinds of tampering, so double compression detection is a basic mean to assess the authenticity of a given image. In this paper, we propose to model the distribution of the mode based first digits of DCT (Discrete Cosine Transform) coefficients using Markov transition probability matrix and utilize its stationary distribution as features for double compression detection. Experiment results show the effectiveness of the proposed method and comparison has been made to show the improvement by using this second order statistical model.