A Novel Image Steganography in Contourletdomain Using Genetic Algorithm

Abstract

Abstract-Steganography is the science that involves communicating secret data in an appropriate multimedia carrier. This paper presents the application of contourlet Transform and Genetic Algorithm (GA) in a novel steganography scheme. We employ a genetic algorithm based mapping function to embed data in Discrete contourlet Transform coefficients in 4x4blocks on the cover image. The optimal pixel adjustment process (OPAP) is applied after embedding the message. GA employed to obtain an optimal mapping function to lessen the error difference between the cover and the stego image and use the block mapping method to preserve the local image properties. Also we applied the OPAP to increase the hiding capacity of the algorithm in comparison with other systems.According to the experimental results, the proposed method is capable of providing a larger embedding capacity without causing noticeable distortions of stego-images in comparison with similar existing methods. Moreoverthe results of our experiments show that employing two of powerful steganalyzers on stego-images produced by our method, they could not discriminate between stego and clean-images reliably.Index Terms-Steganography, discrete contourlet transform, genetic algorithm, optimal pixel adjustment process.