Multilevel reversible data hiding Multilevel reversible data hiding based on histogram modification based on histogram modification

of difference imagesof difference images

Authors: Chia-Chen Lin, Wei-Liang Tai, and Chin-Chen ChangSource: Pattern Recognition, vol. 41, no. 12, pp. 3582-3591, 2008Presenter: Chia-Chun Wu ( 吳佳駿 )Date: 2009/09/04

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Outline

IntroductionRequirementsRelated work

"Reversible Data Hiding," Z. Ni, Y. Q. Shi, N. Ansari, and S. Wei, IEEE Transactions on Circuits and Systems for Video Technology, vol. 16, no. 3, pp. 354-362, 2006

Proposed SchemeExperimentation & Comparison Conclusions

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要解決的問題

此篇論文主要是利用一般影像比較平滑，相鄰兩個像素值非常相近 ( 差值很小 ) 的特性，因此差值介於 -1 ~ +1之間的個數佔了大多數，此時，統計差值取絕對值後的數量，以差值最多的當成Peak bin，結合Ni等人提出來的直方圖無失真資料隱藏的方法，藉由調整相鄰兩個像素的差值，便可以達到高容量、低失真的無失真資料隱藏的目的。

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Introduction

Data hiding

Reversible data hiding

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Requirements

1. Payload Size2. Image Quality3. Reversible

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Ni et al.’s scheme (1/2)

Embedding

1 2 　　 3 　　 4 　 5 　 6

pixel value

8

6

4

2

0

number

Cover image

1 2 4 2

2 3 1 2

3 6 4 2

3 2 3 2

Cover image’

1 2 5 2

2 4 1 2

4 6 5 2

4 2 4 2

Secret { 1, 0, 0, 0, 1, 0, 1 }

1 2 4 2

2 3 1 2

3 6 4 2

3 2 3 2

Cover image’

1 2 5 2

2 4 1 2

4 6 5 2

2 2 4 2

1 3 5 2

2 4 1 2

4 6 5 3

4 2 4 3

Stego image

{0} {1}

Peak bin Zero bin

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Ni et al.’s scheme (2/2)

Extracting & Recovering

1 2 　　 3 　　 4 　 5 　 6

pixel value

8

6

4

2

0

number

Peak bin Zero bin

Cover image

1 2 4 2

2 3 1 2

3 6 4 2

3 2 3 2

Cover image’

1 2 5 2

2 4 1 2

4 6 5 2

4 2 4 2

Cover image’

1 3 5 2

2 4 1 2

4 6 5 3

4 2 4 3

Stego image

1 3 5 2

2 4 1 2

4 6 5 3

4 2 4 3{0} {1}

Secret { 1, 0, 0, 0, 1, 0, 1 }

1 2 5 2

2 4 1 2

4 6 5 2

4 2 4 2

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A BC D

Proposed Scheme (1/6)

Cover image

Histogram Modification

Histogram Modification

Histogram Modification

Histogram Modification

A BC D

A’ B’C’ D’

Stego image

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Proposed Scheme (2/6)

Create the histogram Cover image

5 3 4 3 5

7 4 3 3 5

3 5 4 3 6

3 4 3 3 8

Difference image

-2 1 1 2

-3 -1 0 2

2 -1 -1 3

1 -1 0 5

Absolute difference image

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

0 1 2 3 4 5pixel value

8

6

4

2

0

number

5 3 4 3 5

7 4 3 3 5

3 5 4 3 6

3 4 3 3 6

-2 1 -1 2

-3 -1 0 2

2 -1 -1 3

1 -1 0 3

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Proposed Scheme (3/6)

Embedding Absolute difference image

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

Secret { 1, 0, 0, 0, 1, 0, 1 }

Absolute difference image’

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

3 1 1 3

4 1 0 3

3 1 1 4

1 1 0 5

3 2 1 3

4 1 0 3

3 1 2 4

1 2 0 3

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

0 1 　　 2 　　 3 　 4 　 5

pixel value

8

6

4

2

0

number

{0} {1}

Peak bin

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Proposed Scheme (4/6)

Stego image generating

Cover image Stego image

5 3 4 3 5

7 4 3 3 5

3 5 4 3 6

3 4 3 3 8

Absolute difference image’

3 2 1 3

4 1 0 3

3 1 2 4

1 2 0 3

For the first two pixels in each row For any residual pixels

?

Difference image’

-3 2 -1 3

-4 -1 0 3

3 -1 -2 4

1 -2 0 3

36 36 3

4

6 3

8 4

6 3

8 4

3 6

6 3

8 4

3 6

3 4

6 3

8 4

3 6

3 4

6 3 5

8 4

3 6

3 4

6 3 5

8 4

3 6

3 4

6 3 5 4

8 4

3 6

3 4

6 3 5 4

8 4

3 6

3 4

6 3 5 4 7

8 4

3 6

3 4

6 3 5 4 7

8 4 3 3 6

3 6 5 3 7

3 4 2 2 5

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Proposed Scheme (5/6)

Extracting & Recovering

0 1 　　 2 　　 3 　 4 　 5

pixel value8

6

4

2

0

number

{0} {1}

Secret { 1, 0, 0, 0, 1, 0, 1 }

Stego image

6 3 5 4 7

8 4 3 3 6

3 6 5 3 7

3 4 2 2 5

Absolute difference image’

3 2 1 3

4 1 0 3

3 1 2 4

1 2 0 3

Absolute difference image

Peak bin

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

3 2 1 3

4 1 0 3

3 1 2 4

1 2 0 3

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Proposed Scheme (6/6)

Recoveringoriginalcover image

Stego image

6 3 5 4 7

8 4 3 3 6

3 6 5 3 7

3 4 2 2 5

Absolute difference image

2 1 1 2

3 1 0 2

2 1 1 3

1 1 0 3

Cover image

5 3 4 3 5

7 4 3 3 5

3 5 4 3 6

3 4 3 3 8

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Experimental results (1/4)

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Experimental results (2/4)

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Experimental results (3/4)

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Experimental results (4/4)

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Conclusions

Proposed a reversible data hiding with large capacity When the algorithm is performed for

nine rounds, the average PSNR is still higher than 30 dB and the average hiding capacity still can reach 1.3 bpp.

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此篇論文之優缺點

優點： 跟 Ni. 等人的方法比起來，此方法不用額外記錄

Zero bin 的資訊。 本方法先將整張 Cover Image 切成四張獨立的

Sub-Image ，分別統計子影像中相鄰兩個像素值的差值，並利用每一張子影像的 Peak bin 來調整相鄰兩個像素值的差值，達到無失真資料隱藏的目的，因此隱藏量會比其它方法高。

缺點： 跟 Ni. 等人的方法比起來，此方法需額外記錄更

多 Peak bin 的資訊。

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