High capacity reversible data embedding and content authentication

We present a high capacity reversible data embedding algorithm. It serves the purpose of both self authentication and reversible data embedding. As the algorithm is reversible, the original digital content (before data embedding) can be completely restored after authentication. We employ two techniques, difference expansion and generalized least significant bit embedding, to achieve very high embedding capacity, while keeping the distortion (the quality degradation on the digital content after data embedding) low. A noticeable difference between our method and others is that we do not need to compress original values of the embedding area. We explore the redundancy in the digital content to achieve reversibility. The paper considers grayscale images only, but our method can be applied to color images and to digital audio and video as well.