Research On Digital Image Watermarking Technology

With the development of digital technology and internet, all kinds of multimedia products are released on the internet include photos, videos and audios. They provide the author and the users very large advantage. But the insecurity and the advantage of digital products are equally existence, because they can be copied and transmitted with low cost and high speed by the pirates. The pirates use the advantage to encroach the author's copyright. So, how to protect the copyright of the digital products with all kinds of methods and how to punish the pirates are more and more urgent. The technology for protection of digital products should be provided besides the law and management as used in tradition copyright. Digital watermarking technology is rapidly developed under such requests of appliance.It is a very effective mean to protect image's episteme copyright that embedding significant digital watermark information in an image which can help to prove who is the owner of the work once the entanglement is sued. This paper discusses the technology of digital watermarking based on transform domains and focuses to the discrete wavelet transform domain. The main main jobs and contributions of the paper are as follows:(1) The basic concept and principle of image digital watermark were introduced and the research achievements of inside and outside country were summed up.(2) The algorithm of preprocessing for image watermark is studied. A kind of effective algorithm of image disorder was proposed, which can increased the difficulty of uncover watermark and secrecy of watermark.(3) The image watermarking techniques based on space domain and transformation domain were discussed and an algorithm of discrete cosine transform to make the place of embedding watermark and detection more...