Quantization Index Modulation Steganography Based on the Nonuniform DCT
Deng Yi①,Zhao Xian-feng②,Feng Deng-guo②
①Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei 230026, China; ②State Key Laboratory of Information Security, Institute of Software, Chinese Academy of Sciences, Beijing 100190, China
Abstract:Steganography based on Quantization Index Modulation (QIM) is being increasingly threatened by steganalysis. This paper improves the existing steganographic methods embedding data in Non-uniform Discrete Cosine Transform (NDCT) domain instead of more commonly used Discrete Cosine Transform (DCT) domain, and proposes the NDCT-QIM image steganography which uses the parameters of NDCT as its secret key. Since the embedded signal disperses in the domain guessed by an attacker, the NDCT-QIM method makes steganalysis difficult to detect the characteristics of steganography. The analysis and experiments show that it improves the covertness of embedded signal, and is more resistant to the commonly used steganalysis methods, including those respectively based on testing gradient energy, histogram, wavelet characteristics, etc.