Image Steganographic Method with Variable Embedding Length

Wu and Tsaipsilas pixel-value differencing method and Chang and Tsengpsilas side-match method are based on the theory that the number of bits which can be embedded is determined by the degree of the pixelpsilas smoothness, or its proximity to the edge of the image. If pixels are located in the edge area, they may tolerate larger changes than those in smooth areas. However, both methods are subject to the fall off the boundary problem (FOBP). This study proposes a new scheme that can solve the FOBP. The experimental results demonstrate that the proposed method resolves the problem, and achieves a higher image quality index value than other methods.