Reversible Data Embedding Using Reduced Difference Expansion

The general difference expansion method uses reversible integer transform to embed information into a digital image and perfectly restores the original image after removing the hidden data. In multilayer embedding applications, the operation of difference expansion may seriously degrade the visual quality of the embedded image. In this paper, we propose a reduced difference expansion method to solve this problem. Theoretically, in the worst case, the proposed method gains 6-dB improvement in visual quality of the embedded image compared with the general difference expansion method. Therefore, the proposed method is suitable for multilayer data embedding.