Alternating Current Prediction For Digital Watermarking System

• Main Authors: Yeh-Cheng Hsiang, 葉呈祥
• Other Authors: Yao-Tien Wang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/27685847764197930679

碩士 === 開南大學 === 資訊管理學系 === 96 === Digital Watermarking is mainly applied for the protection of intellectual property. It undergoes several processing to embed watermark into multimedia such as test file, static images, dynamic images and audio signals for purpose of protecting intellectual property. This article proposes a kind of blind watermarking technique which information is embed without access to the host data. This paper uses the Integer Discrete Cosine Transformation (IntDCT) which is used in the H.264 translate algorithm. Three new watermarking systems are proposed. In this paper the first method is to select every nine 4×4 blocks as one group, in which watermark bits can be embedded by modulating the AC(0,1),AC(1,0). The second method is to select every nine 4×4 blocks as one group, in which watermark bits can be embedded by modulating the AC(1,1). The third is to select every nine 4×4 blocks as one group, in which watermark bits can be embedded by modulating the AC(1,1) according to the rule of DC value in the center block. The experiments show that the first and second methods are robust. The third method is robust against compression attacks, but is vulnerable other attacks. It is a good kind of weak watermarking system.