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多媒體網路安全實驗室
Embedding Capacity Raising in
Reversible Data Hiding Based on
Prediction of Difference Expansion
Source: Journal of Systems and Software, Vol. 83, No. 10, pp.
1864-1872, 2010.
Authors: Chin-Feng Lee, Hsing-Ling Chen, and Hao-Kuan Tso
Speaker: Cheng Hsu
Date: 2011/02/23
多媒體網路安全實驗室
Outline
1. Introduction
2. Related works
3. Proposed scheme
4. Experimental results
5. Conclusions
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1. Introduction
The study presents an adaptive reversible
data scheme based on the prediction of
difference expansion.
1. The location map is no more required
2. The embedding capacity can be adjusted
depending on the practical applications
3. The high embedding capacity with minimal
visual distortion can be achieved.
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2. Related works
2.1 Difference expansion technique
embedding phase
extracting phase
u  v 
d  u  v and l  
 2 
d' 2 d  s
 u 'v' 
d '  u 'v' and l '  
 2 
d ' mod 2  s
 d '
d  
2
 d  1
d 
u l
and v  l   

 2 
2
 d '1
 d '
u'  l  
and v'  l   

 2 
2
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2.2 Tseng and Hsieh’s scheme
predictive pixel
Iˆ x, y   ( I ( x  1, y )  I ( x, y  1)) / 2
d  I ( x, y )  Iˆ( x, y )
embedding phase
 2
 2  d  T
3. d  T  T
1. T
 
 
 Iˆ( x, y )  T , if I ( x, y )  Iˆ( x, y )
 Iˆ( x, y )  2  d  s, if I ( x, y )  Iˆ( x, y )

2
I ' ( x, y )  
I
'
(
x
,
y
)


 Iˆ( x, y )  2  d  s, otherwise
 Iˆ( x, y )  T 2 , otherwise
2. T  d  T  T
2
4. 0  d  T
2
 Iˆ( x, y )  T , if I ( x, y )  Iˆ( x, y )
I ' ( x, y )  I ( x, y )

2
I ' ( x, y )  
 Iˆ( x, y )  T 2 , otherwise
 
 
 
 
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extracting phase
Iˆ' ( x, y )  ( I ' ( x  1, y )  I ' ( x, y  1)) / 2
 2
s  d '2  d '
1. T  d '  2T
 Iˆ' ( x, y ) 

I ( x, y )  
 Iˆ' ( x, y ) 
2. T  d '  T
2
 Iˆ' ( x, y ) 

I ( x, y )  
 Iˆ' ( x, y ) 
 
3. d '  2T
d ' 2 , if I ' ( x, y)  Iˆ' ( x, y)
d ' 2 , otherwise
 
 
 Iˆ' ( x, y )  T , if I ' ( x, y )  Iˆ' ( x, y )

2
I ( x, y )  
 Iˆ' ( x, y )  T 2 , otherwise
4. 0  d '  T
2
I ( x , y )  I ' ( x, y )
 
T 2 , if I ' ( x, y)  Iˆ' ( x, y)
T 2 , otherwise
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3. Proposed scheme
Example results of the embedding procedure
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Embedding phase
81
85
81
87
87
87
T=2
Cover image
81
85
87
89
81
Stego image
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81
85
81
T=2
87
87
87
I (3, 2)  87
Cover image
81
85
81
87
89
90
Stego image
Iˆ(3, 2)  (81  87) / 2  84
d | 87  84 | 3
 I ( x, y )  (T  1), if Iˆ( x, y )  I ( x, y ),
I ' ( x, y )  
 I ( x, y )  (T  1), otherwise .
I ' (3, 2)  I (3, 2)  T  1  87  3  90
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Example details of the embedding procedure
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Extracting and recovery phase
81
85
81
T=2
87
89
90
I (2, 2)  89
Stego image
81
85
87
87
81
Cover image
Iˆ(2, 2)  (85  87) / 2  86
d  | Iˆ( x, y )  I ( x, y ) || 89  86 | 3
s  LSB(d )  1

 Iˆ( x, y )  d  / 2, if Iˆ( x, y )  I ( x, y ),
I ( x, y )  
ˆ

 I ( x, y )  d  / 2, otherwise .
I (2, 2)  Iˆ(2, 2)  d  / 2  86  3 / 2  87
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81
85
81
T=2
87
87
90
I (3, 2)  90
Stego image
81
85
81
87
87
87
Cover image
Iˆ(3, 2)  (81  87) / 2  84
d  | 90  84 | 6
 I ( x, y )  (T  1), if Iˆ( x, y )  I ( x, y ),
I ( x, y )  
 I ( x, y )  (T  1), otherwise .
I (3, 2)  I (3, 2)  (T  1)  90  3  87
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Example details of extracting and restoring procedure
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Image histogram. (a) Original distribution and
(b) shrinkage of image distribution
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Histogram modification.
多媒體網路安全實驗室
4. Experimental results
Capacity-distortion for all images tested by the proposed scheme
at varying thresholds
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5. Conclusions
In this paper, they proposed a reversible
data hiding technique. The experimental
results show that the hiding capacity of the
proposed scheme is high.
In addition, the image quality of the
proposed scheme is better than that of
other schemes.
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