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Reversible Data Hiding Based on Two-Dimensional Prediction Errors. 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
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Reversible Data Hiding Based on Two-Dimensional Prediction Errors 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
Yang’s Proposed scheme Proposed scheme (2/6) Embedding Process of odd columns P1 P2 Z2 Z1 H
Yang’s Proposed scheme Proposed scheme(3/6) Embedding Process of odd columns • Rule: • Embed bit 0, keep unchanged • Embed bit 1, P2 -1 or P1 +1, respectively B1=01110011001 D’
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.
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) (2,2) (2,2) Prediction error e1 (2,2) Cover image X For example : x1’(2, 2) = (150+150+150+153)/4 = 150 x2’ (2, 2) =(150+150)/2 = 150 Prediction error e2
Proposed scheme(chessboard, C-2D) pr pl c = 0 e1 e2 Cover image X Result after histogram H(e1, e2) e’1 e’2 Result after shifting Result after shifting channel 0
Proposed scheme(chessboard, C-2D) pr = (0, 0) pl = (-2, -2) Secret bit : 1001110(2) e”2 e’2 e’1 e”1 Result after shifting Stego image Y
Proposed scheme(chessboard, C-2D) pr = (0, 0) pl = (-2, -2) Stego image Y e”1 Secret bit : 1001110(2) Cover image X
Proposed scheme(framework) c ∈ [−cb, cb] Channel 0 (e1, e2) : denote the two prediction errors for a pixel Part of a practical histogram H(e1, e2) generated from Lena
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.