Image Steganographic Scheme Using Tri-way Pixel-Value Differencing and Adaptive Rules

A novel steganographic approach based on tri-way pixel-value differencing (TPVD) is presented in this paper. This approach uses three different directional edges to design the tri-way differencing scheme and to remove the capacity limitation of the original PVD method using only one direction. In addition, we propose an optimal selection approach for the reference point and adaptive rules to reduce distortion from setting larger embedding capacity. The theoretical estimation and experimental results demonstrate that our scheme can provide a superior embedding capacity and the embedded confidential information can be extracted from stego-images without the assistance of original images.