A Study of Hybrid Watermarking for Digital Halftone Images
| Autor: | Yi-Chih Yeh, 葉宜治 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 In this thesis, a hybrid watermarking for digital halftone images was proposed. At first, the spatial watermarking was adopted by the ordered dithering technique which uses two dither cells in the digital halftoning. In view of the shortcomings of the spatial watermarking, the spatial watermarked halftone image was divided into sub-images with 8x8 pixels and transformed by binary pseudo-wavelet transform. The frequency watermarking was embedded into the high frequency components of the designated sub-images. Finally, the donut Masks Zernike moment is adopted to detect rotation and scale of the Hybrid watermarked halftone image. Experimental results show that the hybrid watermarked halftone image with high transparency and the is robust to the malicious attacks such as corrupting, cropping, rotating, scaling, salt & pepper noise. The correct decoding rate is close to 0.9 after the attack of print & scan. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|