Reversible Watermarking Algorithm of General Difference Expansion Based on Sort and De-noise

The location map used in reversible watermarking has two disadvantages.Firstly, the size of the compressed location map is large.Secondly, compression of location map consumes lots of computation.A reversible watermarking scheme of high payload is proposed without location map.The host image is divided into blocks, the smooth degree of each block is computed, which is unchanged after data embedding, according to the smooth degree all blocks are sorted, noised blocks are filtered, watermark is embedded into the selected blocks with the general difference expansion.The experimental results show the proposed method can conceal more information than other methods at the same PNSR.