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Source: The Journal of Systems and Software. Adaptive reversible data hiding based on block median preservation and modification of prediction errors. Author: H. Y. Leung, L. M. Cheng, F. Liu, Q, K, Fu. Department of Electronic Engineering City University of Hong Kong, Hong Kong.
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Source: The Journal of Systems and Software Adaptive reversible data hiding based on block median preservation and modification of prediction errors Author: H. Y. Leung, L. M. Cheng, F. Liu, Q, K, Fu Department of Electronic Engineering City University of Hong Kong, Hong Kong Speaker: Mick Huang 2014/02/24 1
Outline • Introduction • Related works • Proposed method • Embedding • Extracting • Experimental result 2
What’s data hiding? Introduction Secret Message 3
Related works Accurate Gradient Selection Predictor (AGSP) vertical -45° horizontal x 45° 4
Proposed method 1- Embedding(1/3) Secret Data Check the all secret messages are embedding? Original Image AGSP first method Propose Second method No Yes Stego Image 5
Proposed method 1- Embedding(2/3) D1=2|15-12|+2|12-10|+2|12-10|+|10-8|+ |10-9|+|10-10| / 9 + 1 = (6+4+4+2+1+0)/9+1 = 2 D2=2|15-10|+2|12-10|+|10-9|+|12-10|+ |10-8| / 7 + 1 = (10+4+1+2+2)/7+1 = 3 Original Image D3=2|15-12|+2|12-9|+|12-10|+|10-10| / 6+ 1 =(6+6+2+0)/6+1= 3 Dmin1 = D1 =2 —> horizontal Dmin2 = D3 =3 —> 45 degree Cmin1 = x horizontal = 15 D4=2|15-10|+2|12-8|+|10-10| / 5+ 1 =(10+8+0) /5+1= 4 Cmin2 = x 45 degree = 10 6
Proposed method 1- Embedding(3/3) Secret Message s=1 Dmin1 = D1 =2 —> horizontal Dmin2 = D3 =3 —> 45 degree Cmin1 = x horizontal = 15 Cmin2 = x 45 degree = 10 11 Original Image 
Proposed method 1- Extracting(1/1) Dmin1 = D1 =2 —> horizontal Dmin2 = D3 =3 —> 45 degree Cmin1 = x horizontal = 15 Cmin2 = x 45 degree = 10 12 Original Image Reversible 8 
Proposed method 2- Embedding(1/5) Sort=5,6,6,6,7,7,8,9,9,9,9,10,10,10,10,10,10,11,11,11,12,12,15,17,17 Bm=10 a=0+0+0+0+0+0+1+1+1+1 =4 Assume T=10 Lk=0 nl=11 n0=6 Sort=5,6,6,6,7,7,8,9,9,9,9,10,10,10,10,10,10, 11,11,11,12,12,15,17,17 nr=8 Image Block 9  
Proposed method 2- Embedding(2/5) Histogram shift EL=2 3 4 3 4 18 20 3 20 2 10   
Proposed method 2- Embedding(3/5) Secret Message s=1011011001011110 EL=2 5 14 15 s=1; 8-EL-s=8-2-1=5 s=0; 12-EL-s=12+2+0=14 s=1; 12-EL-s=12+2+1=15 11    
Proposed method 2- Embedding(4/5) Secret Message s=1011011001011110 EL=1 7 12 s=1; 9-EL-s=9-1-1=7 13 s=0; 11+EL+s=11+1+0=12 7 8 13 8 s=1; 11+EL+s=11+1+1=13 s=1; 11+EL+s=11+1+1=13 s=0; 9-EL-s=9-1-0=8 s=0; 9-EL-s=9-1-0=8 s=1; 9-EL-s=9-1-1=7      12
Proposed method 2- Embedding(5/5) Secret Message s=1011011001011110 EL=0 10 11 11 11 9 q=1,s=0; unchanged 10 q=2,s=1; 10+1=11 q=3,s=1; 10+1=11 q=4,s=1; 10-(-1)^(4+1)=10-(-1)=11 q=5,s=1; 10-(-1)^(5+1)=10-(1)=9 q=6,s=0; unchanged       13
Proposed method 2- Exacting(1/4) Sort=2,3,3,3,4,4,5,7,7,8,8,9,10,10,11,11,11,12,13,13,14,15,18,20,20 EL=0 s=0 s=10 s=110 Stego Block s=1110 s=11110 s=011110        14
Proposed method 2- Exacting(2/4) EL=1 if d’’k(i,j)= 3 or -3 then s=1 if d’’k(i,j)= 2 or -2 then s=0 s=011110 Stego Block s=1011110 s=01011110 s=001011110 s=1001011110 s=11001011110 s=011001011110 s=1011001011110         15
Proposed method 2- Exacting(3/4) EL=2 if d’’k(i,j)= 5 or -5 then s=1 if d’’k(i,j)= 4 or -4 then s=0 Stego Block s=1011001011110 s=11011001011110 s=011011001011110 s=1011011001011110          16
Proposed method 2- Exacting(4/4) EL=0 6 10 10 9 10 6 10 7 8 7 15 11 12 12 17 EL>0 6 6 11 10 17 9 10 9 9 11 Stego Block           17
Experimental result 18