a lossless robust data hiding scheme

A Lossless Robust Data Hiding Scheme

Source ： PATTERN RECOGNITION Authors ： Xian-Ting Zeng, Ling-Di Ping,

Xue-Zeng PanSpeaker ： Nguyen Thai SonDate ： 2009/11/19

2

Outline Related works Proposed scheme Experimental results Conclusions

3

Related works(1/5) Ni’s scheme

n

iii ba

n 1)(1

α = [(5-7)+(205-202)+(200-203) +(201-206)+(208-207)+(207-201) +(205-204)+(209-202)]/8 =1

ib

ia

5 7 205 202203208204

200 206 201207 207 201205 202 209

I

Cover image

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Related works(2) - Ni’s scheme

5

Related works(3) - Ni’s scheme

EmbedBit 0

EmbedBit 1

5 7 205 202203208204

200 206 201207 207 201205 202 209

5 7 205 202203208204

200 206 201207 207 201205 202 209

15 7 215 202203218204

210 206 211207 217 201215 202 219

0 255Category 2

β β Case 1：-K<α ≤ K

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Related works(4) - Ni’s scheme

0 K-K

α

K = 5，α = 60 K-K

α α'β

β = 2K = 10α' = 16

EmbedBit 1

ErrorCorrection

Code

0 K-K

α

K = 5，α = -7

EmbedBit 0

0 K-K

ErrorCorrection

Code

α'

7

Related works(5) - Ni’s scheme

252 3 13 52242

83 59

62 48 58

73 60 62

69 75 73

embedding 1242 3 3 52242

73 59

52 48 48

73 50 62 59 75 63

original block #1Case 1 of category 2

α= -3

original block #2Case 2 of category 4

α= 7

252 3 13 52242

83 59

62 48 58

73 60 62

69 75 73

embedding 0

With K=5,

compute β= 2K = 10

8

The proposed scheme (1/5)

n

iii ba

1)(

α = [(5-7)+(205-202)+(200-203) +(201-206)+(208-207)+(207-201) +(205-204)+(209-202)] =8

ib

ia

I

Cover image C

5 7 205 202203208204

200 206 201207 207 201205 202 209

Ck is block kth

Foundation of the propose scheme

9

The proposed scheme- T and G are 2 thresholds

- Explore extra space S1

),(

),(),(

),( 1

1

1

jiCjiCjiC

jiSk

k

k

otherwisejiandTjiandT

)2,mod()2,mod()2,mod()2,mod(

The distribution of αbefore applying extra space

The distribution of αafter applying extra space

nmTG 2)2(

1

10

The proposed scheme

1. Embedding bit 0, this block remains intact

),(

),(),(

),(

1

21

21

jiSjiSjiS

jiS

otherwise

jiandTjiandT

)2,mod()2,mod(0,)2,mod()2,mod(,0

nmTG 2)(

2

2. Embedding bit 1, the shifting rule like that:

Embedding Processes [-T,T]

11

The proposed scheme

when embedding bit 0, α [-T, T], bit-0-zoneWhen embedding bit 1, α [T+G, 2T+G] or [-(2T+G),-(T+G)], bit-1-zone

12

The proposed scheme

152)(2

nm

GT

-Example embedding processes :

TT

α = 8

T = 120

G = 0

Extra space S1

),(

),(),(

),( 1

1

1

jiCjiCjiC

jiSk

k

k

otherwisejiandTjiandT

)2,mod()2,mod()2,mod()2,mod(

5 7 205 202203208204

200 206 201207 207 201205 202 209

Original block

5 7 205 202203208204

200 206 201207 207 201205 202 209

5 7 205 202203208204

200 206 201207 207 201205 202 209

EmbedBit 0

EmbedBit 1

5 7 205 202203208204

200 206 201207 207 201205 202 209

),(

),(),(

),(

1

21

21

jiSjiSjiS

jiS

otherwise

jiandTjiandT

)2,mod()2,mod(0,)2,mod()2,mod(,0

20 7 220 202203223204

215 206 216207 222 201220 202 224

Stego block

13

The proposed scheme

1 Compute the value of α of block2 If α [-T, T], bit-0-zone, a bit 0 is extracted

if α [T, 2T+G] or α [-(2T+G),-T], bit-1-zone, a bit 1 is extracted3. The cover image can be recovered by:

Extracting Processes

otherwisejiSjiandGTjiSjiandGTjiSjiandTGTjiSjiandGTTjiS

jiR

),()2,mod()2,mod(2),()2,mod()2,mod(2),()2,mod()2,mod(),2(),()2,mod()2,mod(2,),(

),(

1

1

2

2

14

The proposed scheme-Example for n extracting processes : T = 120

G = 05 7 205 202

203208204

200 206 201207 207 201205 202 209

α = 8

and α [-T,T]

Extract bit 0

α = 128

and α [T, 2T+G]

Extract bit 1

5 7 205 202203208204

200 206 201207 207 201205 202 209

Original block

20 7 220 202203223204

215 206 216207 222 201220 202 224

Stego block

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Experimental results

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Conclusions High embedding capacity and

robustness Simple and efficient Can be applied to various images

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