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Object Watermarking for MPEG-4 Video Protection
Roberto Caldelli,Mauro Barni,Franco Bartolini,Alessandro Piva 에스케이텔레콤 (주) 2002 Telecommunications Review Vol.12 No.5
The MPEG-4 standard is appearing to be very attractive for a large set of applications. In most of them, such as video distribution over mobile and fixed open networks, a copy protection system allowing to control and trace the delivery of multimedia data is required. A new technology useful for copyright protection and media identification is watermarking: a digital code (watermark), bringing information about the copyright owner, is directly embedded into the video signal without degrading its quality. The possibility of the MPEG-4 standard to directly access objects within a video sequence, introduces some new constraints to the classic watermarking process. Further to the classical requirements regarding video watermarking, two features appear to be important in the framework of MPEG-4 applications: first of all, object watermarking should be dealt with, second, the possibility to identify the presence of watermarked objects also after the video sequence has been encoded in another format should be granted. The method proposed in this paper satisfies the two previous requirements by relying on an image watermarking algorithm which embeds the code directly in the video objects. The watermark is inserted by modifying some Discrete Wavelet Transform (DWT) coefficients of the Video Objects extracted from each frame of the video sequence.