The Research Of Digital Watermark And Its Application In Forensic Images Processing System

With the rapid development of digital images processing, It turns to be easy to modify digital images and the result is more and more similar to the original images. As the most important evidence, the images always decided the result that made by policemen and judges. The illegal modification of images could get the expected result. The serious infection was focused on by policemen and the departments concerned and should be solved urgently.Fragile watermark is the efficient way to judge whether the images were changed or not. The dissertation research the issue based watermark. Firstly, I investigated the forensic images and get results that the watermark in forensic images should be fragile and they should found the tiny change in images, on the other hand the watermark should be robust to some common image process, for example, adjust brightness and filter. After that, I found out a lot of watermark arithmetic and do research on them. Finally, two method were bring out aim at the two attributes:(1) the watermark based LU decomposition and Arnold transfer.(2) the watermark based JND and wavelet decomposition. They were put into works and run well.