New image steganography via secret-fragment-visible mosaic images by nearly-reversible color transformation

Abstract

A new image steganography method is proposed, which creates automatically from an arbitrarily-selected target image a so-called secret-fragment-visible mosaic image as a camouflage of a given secret image. The mosaic image is yielded by dividing the secret image into fragments and transforming their color characteristics to be those of the blocks of the target image. Skillful techniques are designed for use in the color transformation process so that the secret image may be recovered nearly losslessly. The method not only creates a steganographic effect useful for secure keeping of secret images, but also provides a new way to solve the difficulty of hiding secret images with huge data volumes into target images. Good experimental results show the feasibility of the proposed method. © 2011 Springer-Verlag.