Research On 3D-DCT Video Watermark Problems

With the development of Internet and wireless, it is easier for people to obtainreal-time image and video over networks. However, content owners also see a highrisk of piracy. So suddenly people become interesting in copyright protection content.there are cryptography and watermarking for copyright protection of content.Cryptography is the earliest technique for copyright protection of digital content, butonce decrypted, the content has no further protection. Watermarking is embedded indigital content. Even after if the digital content is decrypted, watermarking canprotect content. This article introduced two parts. One is the research of watermarkingbased on three dimension discrete cosine transform(3D-DCT), another is therealization of digital rights manage(DRM) in television over internet protocol(IP TV).First, this article introduces the basal theory of video watermarking and theproduction recently. It includes the communication-based models of watermarking,geometric models of watermarking and the modeling watermark detection bycorrelation. we present some type of video watermarking by space domain,frequencydomain and compressed video domain.Secondly, this article introduces a 3D-DCT based model of videowatermarking, and recommends a robust embedded and detected watermarkingprocedure based discrete cosine transform(DCT). According to the detection ofmovement and the model of human visual system, the watermark is embedded inblock sequence of video scene. Before embedding watermark some coefficients of3D-DCT and scaling coefficients are selected. It ensures the invisibility and capacityof watermark. The procedure conquers the limitation of traditional watermarking inresistance to some attacks. Experiment demonstrate the invisibility,attack restanceand capacity of the procedure is good.Thirdly, this article realizes and researches the DRM technique over IP TV.DRM system is parted to two parts. One is encryption system, another is watermarksystem. Two parts have both introduced in particular. In detail every model andinterface of encryption is introduced. Data Encryption Standard(DES) is used toencrypted the coefficient of DCT and confused the coefficient of DCT in one segment.RSA encryption technique is used to encrypt the certificate of client. Experimentdemonstrate its feasibility. Watermarking system adopts the procedure thatwatermark is embedded in compressed video bit stream. The embedding anddetecting of watermark can be modeled and complication is simple.