ABSTRACT
The demands of the aforementioned applications can be met by reversible watermarking techniques. Unlike their robust counterparts, reversible watermarking techniques are fragile and employ an embedding process that is completely reversible. This technique uses the difference expansion of a generalized reversible integer transform, which allows the technique to provide a higher embedding capacity at a lower noise level than all of the other published techniques. Watermarking valuable and sensitive images such as artworks and military and medical images presents a major challenge to most watermarking algorithms. First, such applications may require the embedding of several kilobytes of data, but most robust watermarking algorithms can embed only several hundred bits of data. Second, the watermarking process usually introduces a slight but irreversible degradation in the original image. This degradation may reduce the aesthetic and monetary values of artwork, and it may cause the loss of significant artifacts in military and medical images.
