Reversible Watermarking by Difference Expansion

Abstract

Reversible watermark has drawn lots of interest recently. Different from other types of digital watermarks, a reversible watermark has a special feature that the original digital content can be completely restored. In this paper we describe a high capacity and high quality reversible watermarking method based on difference expansion. 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.