| Summary: | 碩士 === 國立交通大學 === 資訊科學系 === 90 === Two methods for authenticating the integrity and fidelity of a MPEG video, and a method for hiding annotations in MPEG videos are proposed in this study. In the first method for video authentication, a fragile watermarking technique is employed, in which authentication signals are embedded in the DCT blocks by setting up even-parity relations among the DCT coefficients. And in the second method for video authentication, a semi-fragile watermarking technique is employed, in which authentication signals are embedded in selected DCT coefficients and MPEG motion vectors. The integrity and fidelity of a video are authenticated by examining the watermark signals extracted from the video. In the proposed method for annotation hiding, a robust watermarking technique is employed, in which an 8´8 DCT block is used to hide exactly one bit of the annotation data, and a voting scheme is utilized in a data extraction process to decide the final extracted annotation data. The proposed methods can be employed to minimize the perceptual degradation of video quality caused by the embedded data. Furthermore, the embedded data may be extracted directly without using the original video sequences. Good experimental results prove the feasibility of the proposed methods.
|
|---|
