Study of Digital Copyright Protection based on Digital Watermarking Technique
| Autor: | Hsin-Hung Hsieh, 謝欣宏 |
|---|---|
| Rok vydání: | 1999 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 87 The main purpose of this thesis is to design a comprehensive applied system which includes processes of hiding, retrieving and recognizing watermarks in order to solve problems concerning the original copyright attribute and to protect authors’ legal right. The three most important issues of this research lie in considerations that the visual quality of the watermark-processed image should be consistent with the original one, the watermark should not be easy to find or to be removed by attackers, and the watermark should be strong enough to work against any kind of image-processing attacks. Moreover, the proposed algorithm should be working well when any arbitrary gray level and meaningful image segments (such as fingerprint, logo, image, etc.) are adopted as watermark. The technique developed here is distinctly different from the pseudo-random sequence technique, which is used by most of researchers in this filed and usually generates watermarks without visual meanings. The most significant feature of the proposed method is that it combines the concept of spread spectrum and Toral Automorphisms developed by Voyatzis. Moreover, Toral Automorphisms is improved in this study to reduce its execution time. And watermarks which apply this algorithm will not easy to be detected. Finally, this improved method also provides effective results for the recognition of watermarks. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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