Digital Image Steganography Algorithm Based on Iterative Blending

Abstract

A novel image steganography algorithm in wavelet domain is presented using the iterative blending method. Using this algorithm, we can hide a secret image with 256 gray levels into another carrier image. By taking full advantage of the masking characteristics of the human visual system, a JND (just noticeable difference) threshold matrix is given pixel by pixel in the image subbands taking into account the texture and the luminance content of carrier image. The secret image is divided into two matrices to make the gray level no more than 16. Then the matrices are adaptively embedded into the wavelet coefficients of the carrier image by iterative blending. The carrier image and the blending parameter can act as the private keys. The experimental results show that the proposed algorithm provides good transparency and is robust to some extent. The technique also can be used in digital watermarking and other digital application areas.