A Data Hiding Method for Few-Color Images

1. A Data Hiding Method for Few-Color Images Pan, Gang, Wu, Zhaohui, and Pan, Yunhe, Acoustics, Speech, and Signal Processing, 2002. Proceedings. (ICASSP '02). IEEE International Conference on , Volume: 4 , 2002 Page(s): IV-3469 -IV-3472 vol.4 Adviser : Dr. Chang, Chin-Chen Reporter : Chi, Kang-Liang Date : 2003/06/03

2. Outline • Introduction • The proposed approach 1. Subblock classification 2. Supblock • Experimental results • Conclusions

3. Introduction Secret key supblock ranking order permutation of same rank supblocks embedding Host images Marked image Critical data

4. The proposed approach Secret image Host image

5. Subblock classification rank = 2 rank = 5 Let threshold = 4

6. Subblock classification

7. Supblock

8. Supblock rank = 2 rank = 5 rank = 4 . . .

9. Supblock rank = 5 rank = 2 rank = 3 . . .

10. Experimental results Fig. 5. Hiding effect on few-color images. (a) the original host image with 8 colors and size 256*256, (b) the marked image after embedding 289 bits, (c) the difference map, 170 pixels changed (in white), (d) the host image with 9 colors and size 339*887, (e) the image embedded 836 bits .

11. Experimental results Fig. 2. Hiding effect on binary image, (a) the original host image with 449*449, (b) the marked image after embedding 612 bits, 303 pixels changed.

12. Experimental results Table 1. Comparison of embeddable blocks at top rank.

13. Conclusions • This paper uses the prioritized subblocks by pattern matching to select the pixels with least visual quality reduction of embedding, and gets a good experimental results. • Future research may be directed toward increasing the data hiding capacity.