1. 1 Adaptive Data Hiding in Edge Areas of Images with Spatial LSB Domain Systems Source: IEEE Transactions on Information Forensics and Security, Vol. 3, No. 3, pp. 488-497, Sep. 2008. Authors: Cheng-Hsing Yang, Chi-Yao Weng, Shiuh-Jeng Wang, and Hung-Min Sun Speaker: Chia-Chun Wu ( 吳佳駿 ) Date: 2008/09/04

2. 2 Outline Introduction Related works The proposed method Experimental results Conclusion

3. 3 Introduction Fixed Data Hiding Cover image Secret data: Stego-image P 1, P 2, P 3, …, P n 0 111… Cover image Secret data: Stego-image P 1, P 2, P 3, …, P n 0 101111010… Adaptive Data Hiding 10011110 10011111

4. 4 Wu et al. ’ s PVD and LSB replacement method [18] H. C. Wu, N. I. Wu, C. S. Tsai, and M. S. Hwang, “Image steganographic scheme based on pixel-value differencing and LSB replacement methods,” Proc. Inst. Elect. Eng., Vis. Images signal Process., vol. 152, no. 5, pp. 611-615, 2005. 47 PiPi 56 P i+1 9 didi Lower-level: 3LSB Higher-level: PVD 40 P i ' 63 P i+1 ' 23 d i ' 000 111 0010100000111111 48 63(-8)40(+8) 55 0011000000110111 48 P i ' 55 P i+1 ' 7 d i '

5. 5 The proposed method (1/5) 47 PiPi 56 P i+1 9 didi |R 1 | = 16, |R 2 |=16, |R 3 |=224 4-4-7 Case 1Case 2 Case 3Case 4

6. 6 The proposed method (2/5) Case 1 63 PiPi 76 P i+1 13 didi 4-4-7 48 P i ' 79 P i+1 ' 31 d i ' 0000 1111 0000 0011000001001111 63 79(-2 4 )48(+2 4 ) 76 0011111101001100 64 MSE=10 MSE=394 MSE=170 647912 486315 P i ' P i+1 ' d i ' 6463 1 Min(10, 394, 170) = 10

7. 7 The proposed method (3/5) Case 2 48 PiPi 79 P i+1 31 didi 4-4-7 63 P i ' 64 P i+1 ' 1 d i ' 1111 0000 0011111101000000 63(-2 4 ) 64(+2 4 )47 80 0011000001001111 48 MSE=226 MSE=2 X 476417 638017 P i ' P i+1 ' d i ' 4780 33 79 Min(226, 226) = 226 d i =33 > 31

8. 8 The proposed method (4/5) Case 3 51 PiPi 82 P i+1 31 didi 4-4-7 48 P i ' 83 P i+1 ' 35 d i ' 0000 0011 0011000001010011 48(+2 4 ) 83(-2 4 )64 82001101010010 51 MSE=170 MSE=234 MSE=394 X 648319 486719 P i ' P i+1 ' d i ' 6467 3 Min(170, 234) = 170 d i =3 < 16

9. 9 The proposed method (5/5) Case 4 48 PiPi 83 P i+1 35 didi 4-4-7 63 P i ' 79 P i+1 ' 16 d i ' 0111111 1001111 0011111101001111 63(-2 7 ) 79(+2 7 )48 83 0011000001010011 P i ' P i+1 ' d i ' 63207 144 207 63 - 2 7 = -1 < 0

10. 10 Experimental results (1/3) Lower-levelHigher-level R 1 =[0, 7]R 2 =[8, 255] Capacity: 883196 bits PSNR: 33.52 dB Capacity: 916010 bits PSNR: 33.01 dB Capacity: 816956 bits PSNR: 37.82 dB Capacity: 874642 bits PSNR: 34.84 dB 3-4 Lower-levelMiddle-level R 1 =[0, 15]R 2 =[16, 47] 3-4-5 Higher-level R 3 =[48, 255]

11. 11 Experimental results (2/3)

12. 12 Experimental results (3/3)

13. 13 Conclusion The proposed method majors in more significant promotion in the term of adaptability, capacity, and imperceptivity.