Reversible Data Hiding Based on Two-Dimensional Prediction Errors
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Transcript of Reversible Data Hiding Based on Two-Dimensional Prediction Errors
Reversible Data Hiding Based on Two-Dimensional Prediction Errors
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Source : IET Image Processing, Vol. 7, No. 9, pp. 805-816, 2013
Authors : Shyh-Yih Wang, Chun-Yi Li and Wen-Chung Kuo
Speaker : Min-Hao Wu
Date : 2014/03/17
Outline
Related work – Yang et al.’s scheme
Proposed scheme
Experimental results
Conclusions
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Yang’s Proposed scheme (1/6)
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Yang’s Proposed scheme Proposed scheme (2/6)
5 5 5 4 4
5 6 4 5 4
5 5 4 5 5
3 4 2 4 4
3 3 4 3 4
0 5 1 4 0
-1 6 -1 5 -1
0 5 -1 5 0
-1 4 -2 4 0
0 3 1 3 1
0
1
2
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5
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-3 -2 -1 0 1 2
0 5 2 4 0
-1 6 -1 5 -1
0 5 -1 5 0
-1 4 -3 4 0
0 3 2 3 20
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-3 -2 -1 0 1 2
P1P2
Z2 Z1
Embedding Process of odd columns
H
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Yang’s Proposed scheme Proposed scheme(3/6)
0 5 2 4 0
-1 6 -1 5 -1
0 5 -1 5 0
-1 4 -3 4 0
0 3 2 3 2 0
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-3 -2 -1 0 1 2
Rule:Embed bit 0, keep unchangedEmbed bit 1, P2 -1 or P1 +1, respectively
B1=01110011001
0 5 2 4 1
-2 6 -2 5 -1
0 5 -2 5 1
-1 4 -3 4 0
1 3 2 3 2 0
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-3 -2 -1 0 1 2
5 5 6 4 5
4 6 3 5 4
5 5 3 5 6
3 4 1 4 4
4 3 5 3 5
Embedding Process of odd columns
D’
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Yang’s Proposed scheme Proposed scheme(6/6)
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Embedding process Step 1:
scan the cover image and apply the two prediction methods to predict the pixel values in the image.
For each scanned pixel, let (e1, e2) denote the prediction errors.
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Embedding process
Step 2:
generate the 2D histogram, H(e1, e2).
Step 3:
split the e1 − e2 plane into channels and partition the histogram H(e1, e2) correspondingly.
Step 4:
select ‘embedding channels (ECs)’, which are the channels for embedding messages.
Step 5:
for each EC, use a 1D embedding technique to embed the message.
Proposed scheme(chessboard, C-2D)
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Cover image X
Prediction error e1
Prediction error e2
(2,2)
(2,2)
(2,2)
For example :x1’ (2, 2) = (150+150+150+153)/4 = 150x2’ (2, 2) = (150+150)/2 = 150
Proposed scheme(chessboard, C-2D)
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Result after histogram H(e1, e2)
Result after shifting channel 0
pr pl
e’1 e’2
e1 e2
Result after shifting
Cover image X
c = 0
Proposed scheme(chessboard, C-2D)
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pr = (0, 0) pl = (-2, -2)Secret bit : 1001110(2)
e’1 e’2
Result after shifting Stego image Y
e”1e”2
Proposed scheme(chessboard, C-2D)
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Stego image Y
pr = (0, 0) pl = (-2, -2)
Secret bit : 1001110(2)
e”1
Cover image X
Proposed scheme(framework)
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(e1, e2) : denote the two prediction errors for a pixel
c [−c∈ b, cb]
Part of a practical histogram H(e1, e2) generated from Lena
Channel 0
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Experimental results
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Conclusions
This scheme can be used to design 2D reversible data-hiding schemes is presented.
This framework can be applied to any architecture, and it can easily be extended into a multi-dimensional framework.