Adaptive Reversible Data Hiding Method Considering the Human Visual System
| Autor: | Mei-Chen Wu, 吳玫珍 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 This thesis improves Jung et al.’s reversible data hiding method published in 2011. Jung et al. employed the mean of visited neighboring pixels to predict the current pixel value, and considering the human visual system (HVS) to estimate the just noticeable difference (JND) of the current pixel. Message bits were then embedded by adjusting the embedding level according to the calculated JND. This method achieved an excellent image quality. However, the neighboring pixels are not fully explored for prediction, and the shifting of absolute value of prediction error histogram may cause a decrease in image quality. The embedding algorithm they used results in over modification of pixel values and a large location map, which deteriorates the image quality and decreases the pure payload. This research exploits the nearest neighboring pixels to predict the visited pixel value and to estimate the corresponding JND. The shifting of prediction error histogram is bi-directional to increase the payload. In addition, the cover pixels are preprocessed adaptively to reduce the size of the location map. This thesis also employs an embedding level selection mechanism to prevent near-saturated pixels from being over modified. Experimental results show that the image quality of this research is higher than that of Jung et al.’s method, and the payload can also be increased due to the reduction of the location map. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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