Research On Digital Watermarking Based On Image Fusion

Recently,the applications of digital multimedia make a rapid progress with the wonderful development of digital technology and the Internet,From the early of 90's, the multimedia data copyright protection method becomes a hot research field,this method mainly based on the tools of digital watermarking and information hiding.Our research is based on fusion digital watermark algorithm.In the view of fusion, the embedding of watermark can be seen as the fusion of the original image and the watermark.Because of this reason,many algorithms which are suitable for image fusion can also be used in digital watermark algorithm and our research is just based on the fusion digital watermark algorithm.We presented two fusion digital watermark algorithm.The first is an adapting digital algorithm based on the chaos and image fusion principle.The watermark image was scrambling pretreatment using chaos map,and then,the Noise Visibility Function of the carrier image was obtained.The carrier image and the watermark image was fused using the NVF of carrier image as fusion-factor for improving the strength of the watermark information adaptively and hiding the information in carrier image.The results showed that visual effect of hiding was improved.The second is a novel digital watermark algorithm which based on Kalman filter. Through unifying the watermark image and the original image for a new state equation and the corresponding measurement equation was given.Digital watermark was converted to data fusion.The optimal estimation in the case of minimum estimation error variance such as the observation of target state in different time with two sensors was given to embed the watermark image into the original image.Two conditions were discussed and each watermark extracting formula was given according to the difference of original image between watermark image observing sequence during parameters selecting and watermark extracting.Multi-group simulation results show that the watermark algorithm of this paper has good robustness and imperceptibility.Performance evaluation is a very important issue,it plays the guiding role in the digital watermark algorithm.In view of information theory,performance indices based on information theory are further analyzed,and then information crossing entropy is proposed successively.At the same time,the effectiveness of the proposed algorithms is shown through computer simulations.