Reserch On Digital Image Security Based On Digital Watermarking

Digital images are more and more widely used in nowadays society. They are much more convenient in editing, storing, transmitting and usage. But unfortunately, due to the malicious modification, digital media become unsafe. Therefore, effective copyright protection and multimedia security are becoming a highlight.This thesis gives a simple architecture for image security system. It based on current communication system, with the form of an IN Provider, meets the needs of an image security system using simple functional entities and service logic.This thesis gives an auto-restorable robust watermarking algorithm for image content authentication, which can not only detect the location of any changes in images but also restore the altered image content. Firstly, the low frequents sector picked up by DWT as watermarking. Then the multiple-based number system is used to reduce the data amount to be embedded, and the RS correct-encode technology and chaotic shuffling technique are used to ensure the invisibility and robustness. Finally, the watermarking data are embed into the intermediate frequency part of the image data. Experimental results demonstrate that the watermarking algorithm has a strong restored ability for attacks.