Scrambling technology for restorable fragile watermarking

In order to analyzing the requirements of restorable fragile watermarking on scrambling technology, this paper proposes a block-based chaotic sorting scrambling method. This method partitions watermark information into blocks, each of which is made different chaotic sorting transformation and moved to corresponding sub-block. The statistical results of contrast test show that this method not only makes every pixel have better displacement and high security, but also has nothing to do with selected key and improves image quality after recovering.