A steganographic scheme based on image scrambling and coding techniques

We propose a new image steganographic method that offers high payload and low distortion. The proposed method affects the image histogram slightly, which will be helpful to resist attacks based on the characteristic function of histogram. We scramble the secret message (especially image format) and cover image to make pixels of all gray scales evenly distributed in image blocks, and use diamond coding method to embed the scrambled secret message into scrambled cover image. Scrambling transform is cyclical, thus the stego-image can be recovered. Experimental results reveal that our approach achieves lower distortion than that of diamond coding method. We also propose an evaluation of image scrambling degree, and the experimental results demonstrate that our evaluation is consistent with visual sensory evaluation.