Reversible watermarking techniques extract the watermark and recover the original image from the watermarked image without any distortion. They have been applied for those sensitive fields, such as the medicine and the military. In this thesis, a novel watermarking algorithm using multi-prediction values has been proposed. It exploits the correlation between the original pixel and the neighboring pixels to obtain twelve prediction candidates, and then selects a candidate as the prediction value according to the original pixel and the temporary prediction value. Due to the algorithm use the original pixel as one of the parameters to decide the prediction value, our prediction values are obtained with great precision.
The experimental results reveal that the performance of our proposed method outperforms that proposed by Sachnev. For example the variance of the prediction errors histogram obtained by the proposed method is less than that obtained by the algorithm proposed by Sachnev et al. about 44.2%; the mean PSNR greater than about 1.47 dB and 1.1 dB under the watermark capacity 0~0.04 bpp and 0.04~0.5 bpp, respectively. Therefore, the proposed method is especially appropriate for embedding watermark in low or medium capacity.
Keyword¡G reversible watermarking, watermarking, prediction, histogram shifting.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0720111-165538 |
| Date | 20 July 2011 |
| Creators | Chen, Nan-Tung |
| Contributors | Chung-Huang Yang, Wen-Shyong Hsieh, Lung-Jen Wang, Ming-Chao Chiang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0720111-165538 |
| Rights | withheld, Copyright information available at source archive |
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