An Energy Efficient and High Security Watermarking Algorithm Based on DS-CDMA
| Autor: | Li-Te Lee, 李立得 |
|---|---|
| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 Recently, digital watermarking is an active technique for the copyright protection. Since the battery life of portable device is restricted, reducing the energy consumption in an embedded system is a crucial goal. In order to implement watermarking scheme for embedded systems, we present an energy efficient, secure and robust watermarking algorithm based on DS-CDMA technique in this master thesis. In this proposed method, multiple watermark patterns are spread with multiple orthogonal spreading codes and then embedded to DCT domain coefficients. In this way, all the capacity, security, and robustness can be improved simultaneously. For power saving, according to the properties of DCT and DS-CDMA technique, we propose a low computational complexity frequency domain transformation for the DS-CDMA embedding. More precisely, we proposed a new architecture for the DS-CDMA based watermarking. Experimental results show that our approach can reduce 82.2% energy consumption. Moreover, the quality measuring results demonstrate that the proposed DS-CDMA watermarking algorithm is robust enough against several signal distortions such as JPEG compression, sharpening, blurring, intensity adjusting, cropping and random noise adding. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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