Improving Reversible Data Hiding Schemes in Encrypted Images before Encryption

This paper describe reversible data hiding in encrypted images, it maintains the excellent property that the original cover can be losslessly recovered after embedded data is extracted while protecting the image content?s confidentiality. The drawback of previous methods embeds data by reversibly vacating room from the encrypted images, which may be subject to some errors on data extraction and/or imag restoration. In this paper, we propose method by reserving room before encryption with a traditional RDH algorithm, and so it is easy for the data hider to reversibly embed data in the encrypted image. The proposed method can achieve real reversibility, that is, data extraction and image recovery are free of any error. Experiments show that this method can embed more than 10 times as large payloads for the same image quality as the previous methods.