Tae-Yun Chung

Digital Watermarking For Copyright Protection Of Mpeg2 Compressed Video

Digital watermarking is the technique which embeds an invisible signal including owner identification and copy control information into multimedia data such as audio, video, images, for copyright protection. This paper proposes a new watermarking technique which is appropriate for the MPEG-2 video coding system by extending the direct sequence spread spectrum. The proposed watermarking scheme in this paper minimizes the perceptual degradation of video quality, caused by the embedded watermark through controlling the strength and area of embedding with respect to the global and local characteristics of the video sequences. And this technique can also directly extract the embedded watermark from the watermarked MPEG-2 compressed video stream without using original video sequences. Simulation results show that the proposed scheme is robust to various attacks to remove the embedded watermark and is feasible for real time system implementation.

Quantization control for improvement of image quality compatible with MPEG2

A new quantization control method for a moving picture coding system, based on MPEG 2 video syntax, is discussed. The quantization control method consists of MB (macro block) activity calculation and rate control. In considering of human visual characteristics and coding efficiency, the quantization control method performs a high quality compression of the digital video signal. >

A private/public key watermarking technique robust to spatial scaling

Digital watermarking is the technique which embeds the invisible signal including owner identification and copy control into multimedia data such as audio, video and images for copyright protection. In this paper, a new watermarking algorithm which embeds information of the copyright owner and copy control using a private/public key and is robust to spatial scaling such as converting the aspect ratio in a screen and resampling for a spatial scalable hierarchy is proposed.