1. 人力資源報告 Image and Signal Processing 1 Steganography Using Sudoku Revisited Wien Hong, Tung-Shou Chen, Chih-Wei Shiu Department of Information Management, Yu Da College of Business, Miaoli, 361,Taiwan Graduate School of Computer Science and Information Technology, National Taichung Institute of Technology, Taichung, 404, Taiwan 1 2 2 1 Speaker Chih-Wei Shiu 1 IITA 2008, Shanghai, China

2. 人力資源報告 Image and Signal Processing 2 Outline Introduction Related works The proposed scheme Experimental results Conclusions

3. 人力資源報告 Image and Signal Processing Introduction 3 03 Cover Image Secret Data Stego-image Extraction Algorithm Embedding Algorithm Extraction Secret Data

4. 人力資源報告 Image and Signal Processing Related works 4 Each of the rows, columns and blocks are filled by the number 0-8 tile Reference matrix M

5. 人力資源報告 Image and Signal Processing Related works 5 12 11 9 7 5 12 15 7 10 13 6 8 12 14 5 9 Original image 61 Secret digits Stego image 125 CE V =M(8,5) CE V 6 EC H CE H =M(12,8) EC B CE B =M(13,3) |12-8|+|5-5|=4 |12-12|+|5-8|=3 |12-13|+|5-3|=3 133 Reference matrix M

6. 人力資源報告 Image and Signal Processing Related works 6 12 11 9 7 5 12 15 7 10 13 6 8 12 14 5 9 Original image 61 Secret digits 133 Stego image 10 12 CE V =M(7,12) CE V 1 CE H CE H =M(10,16) CE B CE B =M(11,13) |10-7|+|12-12|=3 |10-10|+|12-16|=4 |10-11|+|12-13|=2 1113 Reference matrix M 11 9 7 12 15 7 13 6 8 14 5 9

7. 人力資源報告 Image and Signal Processing 7 The proposed scheme 12 11 9 7 5 12 15 7 10 13 6 8 12 14 5 9 Original image 61 Secret digits CE V =M(8,5) CE V 6 CE H CE H =M(12,8) CE B CE B =M(13,3) |12-8|+|5-5|=4 |12-12|+|5-8|=3 |12-13|+|5-3|=3 Reference matrix M 6 15 8 6 7 3 4 7 6 3 5 EC A =M(11,6) |12-11|+|5-6|=2 CE A

8. 人力資源報告 Image and Signal Processing Experimental Results 8 Comparison of stego image quality

9. 人力資源報告 Image and Signal Processing Conclusions The proposed method introduces an additional set of candidate elements CE A for referencing. image quality outperform Chang’s method at the same embedding capacity. 9

10. 人力資源報告 Image and Signal Processing Thanks for your listening 10