Reversible watermark with large capacity using the predictive coding

A reversible watermarking algorithm with large capacity has been developed by applying the difference expansion of a generalized integer transform. In this algorithm, a watermark signal is inserted in the LSB of the difference values among pixels. In this paper, we apply the prediction errors calculated by a predictor in JPEG-LS for embedding a watermark signal, which contributes to increase the amount of embedded information with less degradation. As one of the drawbacks discovered in the above conventional method is a large size of the embedded location map introduced to make it reversible, we decrease the large size of the location map by vectorization, and then modify the composition of the map using the local characteristic in order to enhance the performance of JBIG2.