1 Adaptive Data Hiding in Edge Areas of Images With Spatial LSB Domain Systems Adviser: Chih-Hung Lin Speaker ： Chia-Wei Chang Date:2009/10/06

2 Introduce of Authors Author:Cheng-Hsing Yang, Chi-Yao Weng, Shiuh-Jeng Wang and Hung- Min Sun. IEEE Transactions on Information Forensics and Security, vol. 3, no. 3, september C.-H. Yang is with the Department of Computer Science, National Pingtung University of Education, Pingtung, 900, Taiwan. C.-Y. Weng and H. M. Sun are with the Department of Computer Science, National Tsing-Hua University, Hsinchu, 300, Taiwan, R.O.C. S.-J. Wang, corresponding author, is with the Department of Information Management, Central Police University, Taoyuan, 333, Taiwan, R.O.C. Manuscript received November 1, 2007; revised March 12, Published August 13, 2008 (projected).

3 Outline Introduction Literature Review Proposed Method  Embedding Procedure  Data Extraction Experimental Results Conclusions

4 I.Introduction

5 embedding = Embedding

6 I.Introduction In 2003, Wu and Tsai proposed a “PVD”. In2004, Chang and Tseng proposed a side-match method. In 2005, Park et al. proposed a steganographic scheme based of neighboring pixels. In 2005, Wu et al. proposed the pixel-value differencing (PVD) and LSB replacement method.

7 I.Introduction LSB techniques PVD techniques Side-Match techniques

8 LSB method Fig.1:Wu et al.’s division of “lower level” and “higher level” (Div=15) 

9 II. Literature Review Wu et al.’s PVD and LSB

10 II. Literature Review Example =|56-47|=9 (lower-level) To embed =63,=40=23>Div=15 If level≠ level =55,=48=55-48=7

11 III.Proposed Method 2-3 Division and Division (a) (b) Fig. 2. Two dividing cases: (a) “lower level” and “higher level” and (b) “lower level,” “middle level,” and “higher level.”

12 III.Proposed Method 2-3 Division Division

13 III-1.Embedding steps for l-m-h

14 III-1.Embedding steps for l-m-h

15 III-1.Embedding steps for l-m-h Case6.1 =L-level ≠L-level Case6.2 =M-level =L-level Case6.3 =M-level =H-level Csae6.4 =H-level ≠H-level

16 III-1 Embedding Procedure Example =|64-47|=17 (middle-level) To embed 4-bit LSB =74,=32=42 =M-level =L-level =74,=48=|74-48|=26 After the modified LSB substitution is applied =58,=48=10

17 III-2.Data Extraction

18 There are 4 bits embedded in and 4 bits embedded in III-2.Data Extraction Example =74,=48=|74-48|=26 ‘s secret bits

19 IV.Experimental Results Fig. 3:Two cover images. (a)Elaine. (b) Baboon.

20 IV.Experimental Results

21 IV.Experimental Results

22 IV.Experimental Results

23 IV.Experimental Results

24 V.Conclusions some l - h divisions and l - m - h divisions both yielded higher capacity and higher PSNR. Embed secret data into gray images without making a perceptible distortion. Can be analyzed automatically, aiming to capture an adequate - - division satisfying the key requirements in information hiding. Experimental results show that our approach obtains both larger capacity and higher image quality than that of Wu et al.