An optimization approach to the TWPVD method for digital image steganography

Abstract

In Digital Image Steganography, Pixel-Value Differencing methods commonly use the difference between two consecutive pixel values to determine the amount of data bits that can be inserted in every pixel pair. The advantage of these methods is the overall amount of data that an image can carry. However, these algorithms frequently either overflow or underflow the pixel values resulting in an incorrect output image. To circumvent this issue, either a number of extra steps are added to adjust those values, or simply the pixels are deemed unusable and they are ignored. In this paper, we adopt the Tri-way Pixel-Value Differencing method and find an optimal pixel value for each computed pixel block such that their difference holds the maximum input data and neither underflow or overflow pixels exist.