# Reversible Data Hiding Based on Two-Dimensional Prediction Errors

## Presentation on theme: "Reversible Data Hiding Based on Two-Dimensional Prediction Errors"— Presentation transcript:

Reversible Data Hiding Based on Two-Dimensional Prediction Errors
Source : IET Image Processing, Vol. 7, No. 9, pp , 2013 Authors : Shyh-Yih Wang, Chun-Yi Li and Wen-Chung Kuo Speaker : Min-Hao Wu Date : /03/17

Outline Related work – Yang et al.’s scheme Proposed scheme
Experimental results Conclusions

Yang’s Proposed scheme (1/6)

Yang’s Proposed scheme Proposed scheme (2/6)
Embedding Process of odd columns P1 P2 5 4 6 3 2 5 1 4 -1 6 -2 3 Z2 Z1 H 5 2 4 -1 6 -3 3

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 5 2 4 -1 6 -3 3 B1= 5 2 4 1 -2 6 -1 -3 3 5 6 4 3 1 D’

Yang’s Proposed scheme Proposed scheme(6/6)

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: Step 3: Step 4: Step 5:
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) = ( )/4 = 150 x2’ (2, 2) = ( )/2 = 150 Prediction error e2

Proposed scheme(chessboard, C-2D)
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)
pl = (-2, -2) Secret bit : (2) e”2 e’1 e’2 e”1 Result after shifting Stego image Y

Proposed scheme(chessboard, C-2D)
pl = (-2, -2) Stego image Y e”1 Secret bit : (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

15

Experimental results

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.