A novel block-based steganographic method

Considering into account the most important requirement of steganography, i.e. producing the minimal distortion, the proposed method changes the arrangement of the pixels of the cover image and finds a route such that the maximal similarity between the LSB of the pixels along this route and the secret data is obtained. In the introduced image steganographic method, a sequence of random numbers is first generated by a pseudo-random number generator (PRNG) with an arbitrary seed. Then the cover image is divided into some blocks with variable sizes using this sequence. Traversing the blocks in a raster scan manner, a route is created and the secret data is embedded into the LSB of the pixels along this route using syndrome-trellis codes. Among the routes created by repeating this process with different seeds, the best route which produces minimal distortion is chosen for data embedding. The experimental results evaluated on 2000 natural images show that our proposed method significantly decreases the image distortion and thus it can enhance the security against steganalysis.