A Robust Multiple Logo-Watermarking Scheme Based on Integer Wavelet Transform
| Autor: | Chen Shih Fong, 陳仕峯 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 This paper proposes an integer wavelet-based multiple logo-watermarking process for the copyright protection of still images. The watermark logo is embedded into integer wavelet coefficients of low-pass and high-pass bands at the first level of discrete wavelet transform decomposition. Based on the properties of modular operation, the algorithm utilizes multiple modular operations with different threshold values to modify the wavelet coefficients. To enhance security, the scramble method is used to permute the meaningful watermark logo, and the one-way deterministic function with specified seed is used to select the location during the watermark embedding. The robustness of the proposed scheme is tested on a series of normal attacks in image processing, such as blurring, cropping, additive Gaussian noise, histogram equalization, JPEG compression, rescaling, rotation, gamma correction, sharpening, and JPEG2000 compression. Moreover, the experimental results and analysis show the performance of this scheme to be superior to that of an existing one. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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