Adjacent quad modification algorithm for reversible data hiding
description
Transcript of Adjacent quad modification algorithm for reversible data hiding
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Adjacent quad modification algorithm for reversible data hiding
Source : Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP), 2010 Sixth International Conference Authors : Hsiang-Cheh Huang, Ting-Wei Chen, Feng-Cheng ChangSpeaker : Jiun-Lwen LiangDate : 2012/12/19
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OutlineIntroductionRelated workProposed scheme◦Embedded◦Extraction
Experimental resultsConclusions
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IntroductionToday, the Internet is a popular channel
that allows users to exchange information without geographic limitations.
Protecting transmitted media is becoming an increasingly important issue.
Reversible data hiding can be classified into two types: ◦Histogram shifting◦Difference value
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Related work 1/4• Step 2: To shift the pixels of histogram
(1) If P>Z → To shift the range of the histogram , [Z+1, P-1], to the left-hand side by 1 unit.
(2) If P<Z → To shift the range of the histogram , [P+1, Z-1], to the right-hand side by 1 unit.
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• Step 3: To hide the secret data by pixels P
(1) If P>Z → To be embedded bit is “1”, the pixel value is changed to P-1. If the bit is ”0”, the pixel value remains.
(2) If P<Z → To be embedded bit is “1”, the pixel value is changed to P+1. If the bit is ”0”, the pixel value remains.
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Original image
2 6 3 1 1
5 2 6 1 1
2 3 5 5 1
3 3 1 2 6
3 3 3 3 2
Peak point Zero point
[3+1,6-1]
4 → 5
5 → 6
0 1 2 3 4 5 6 70
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6
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2 5 3 1 1
4 2 5 1 1
2 3 4 4 1
3 3 1 2 5
3 3 3 3 2
P=3, Z=6 and P<Z shift to right-hand
Related work 2/4
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2 6 4 1 1
5 2 6 1 1
2 4 5 5 1
3 3 1 2 6
4 4 3 4 2
Using P=3,
0 → 3
1 → 4
Secret bits: 1 1 0 0 1 1 0 1
0 1 2 3 4 5 6 70
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5
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2 6 3 1 1
5 2 6 1 1
2 3 5 5 1
3 3 1 2 6
3 3 3 3 2
Marked image
Related work 3/4
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2 6 4 1 1
5 2 6 1 1
2 4 5 5 1
3 3 1 2 6
4 4 3 4 2 3 → 0 4 → 1Marked image
P=3, Z=6
Extract
2 6 4 1 1
5 2 6 1 1
2 4 5 5 1
3 3 1 2 6
4 4 3 4 2
Extracted secret bits:1 1 0 0 1 1 0 1
2 5 3 1 1
4 2 5 1 1
2 3 4 4 1
3 3 1 2 5
3 3 3 3 2
6 → 5 5 → 44 → 33 → 3
Recover
Original image0
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0 1 2 3 4 5 6 7
Related work 4/4
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Original image
DC
BA
2 X 2
161162
163162
2 X 2
difference :
abb PPd
acc PPd
add PPd
1162163 bd
1162161
0162162
d
c
d
d
Proposed scheme
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TH = 1
TH-TH
1
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4
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Difference histogram
0-4 -3 -2 -1 0 1 2 3
TH dd'd
Case
iii ,1
1
TH ddd
Case
ii'i ,1
2
THd , -THdd
Case
ii'i
3-10
1162
2 X 2
d
-10
1162
2 X 2
d’
Proposed scheme
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1
23
4
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Difference histogram
0-4 -3 -2 -1 0 1 2 3
S = 1 0
S = 1
TH; ddd
TH; ddd
i'i
''i
i'i
''i
1
1
S = 0
THTH,d; ddd 'i
'i
'i
''i
Embed 1Embed 1
TH = 1
Embed 0
-10
2162
2 X 2
d’’
-10
1162
2 X 2
d’
Proposed scheme-Embedded 1/2
1642162 bS
161)1(162
1620162
d
c
S
S
''bab dPS
''cac dPS ''
dad dPS
Stego pixels:
161162
164162
2 X 2-10
2162
2 X 2
d’’ Stego image
Proposed scheme-Embedded 2/2
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161162
164162
2 X 2
Stego image
difference :
abb SSd ''
acc SSd ''
addSSd ''
-10
2162
2 X 2
difference
Proposed scheme-Extraction 1/3
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1
23
4
5
6
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Difference histogram
0-4 -3 -2 -1 0 1 2 3
-10
2162
2 X 2
d’’
S : 11
1''
''
THd
THd
i
i
S : 0
THd
THd
i
i
''
''
TH = 1
Extract S=1
Extract S=0
-10
1162
2 X 2
d‘
d’b = 1
d’d = -1
Proposed scheme-Extraction 2/3
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1
23
4
5
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Difference histogram
0-4 -3 -2 -1 0 1 2 3
TH = 1
-10
1162
2 X 2
d’
161162
163162
2 X 2cover pixels
TH-TH
Proposed scheme-Extraction 3/3
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Original image TH=1 , PSNR =50.29db
Capacity=34423bits
Experimental results 1/4
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The image quality and the capacity with the Lena image.
TH
Experimental results 2/4
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Experimental results 3/4
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The image quality and the capacity under several modification levels with the Lena image.
Experimental results 4/4
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ConclusionsHigher capacity and better image quality.
• The combinations of threshold values provided the increased flexibility for data protection.