Reversible Data Hiding Based on Two-Dimensional Prediction Errors

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Source : IET Image Processing, Vol. 7, No. 9, pp. 805-816, 2013Authors : Shyh-Yih Wang, Chun-Yi Li and Wen-Chung KuoSpeaker : Min-Hao WuDate : 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 45 6 4 5 45 5 4 5 53 4 2 4 43 3 4 3 4

0 5 1 4 0-1 6 -1 5 -10 5 -1 5 0-1 4 -2 4 00 3 1 3 1

0

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5

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-3 -2 -1 0 1 2

0 5 2 4 0-1 6 -1 5 -10 5 -1 5 0-1 4 -3 4 00 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 -10 5 -1 5 0-1 4 -3 4 00 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=011100110010 5 2 4 1-2 6 -2 5 -10 5 -2 5 1-1 4 -3 4 01 3 2 3 2 0

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-3 -2 -1 0 1 2

5 5 6 4 54 6 3 5 45 5 3 5 63 4 1 4 44 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.