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A Novel Fast Self-restoration Semi-fragile Watermarking
Algorithm for Image Content Authentication Resistant to
JPEG Compression
Hui Wang, Anthony TS Ho and Xi Zhao
24th October 2011
02/18
• Background
Image Content Authentication and Self-Restoration
Problem? How to solve?
• Proposed Watermarking Method
Watermark Generation, Embedding and Extracting;
Image Authentication;
Image Restoration
• Experimental Results and Analysis
• Conclusion and Future Work
Outline
H. Wang, A.T.S. Ho and X. Zhao
03/18 H. Wang, A.T.S. Ho and X. Zhao
Background
Fragile
Semi-fragile
Authentication
Self-restoration Watermarking techniques for
•Technical Requirements:
1.Imperceptibility 2.Robustness 3.Security
•The Problem:
•Solution Approach: •Solution Approach:
•The Problem:
04/18
Background
H. Wang, A.T.S. Ho and X. Zhao
Watermarked Image
Authentication
& Restoration
Extracted Watermark Generated Watermark
•Solution Approach:
03/18 H. Wang, A.T.S. Ho and X. Zhao
Background
•The Problem:
Fragile
Semi-fragile
Authentication
Self-restoration Watermarking techniques for
•Solution Approach:
1.Imperceptibility 2.Robustness 3.Security
•Technical Requirements:
05/18
Proposed Watermarking Method
H. Wang, A.T.S. Ho and X. Zhao
Mapping Function :
From location(i,j)
to location (i’, j’)
1.Embedding Method:
06/18 H. Wang, A.T.S. Ho and X. Zhao
Method for embedding and detecting authentication watermark:
Quantization Index Modulation (QIM)[16]
[16] B. Chen and G. W. Wornell, "Quantization index modulation: a class of provably good methods for digital watermarking and information embedding", IEEE Trans. Inf. Theory, vol. 47, no. 4, pp.1423 - 1443 , 2001.
07/18 H. Wang, A.T.S. Ho and X. Zhao
Proposed Watermarking Method
2.Authentication
and Restoration Method:
08/18 H. Wang, A.T.S. Ho and X. Zhao
Proposed Watermarking Method
Generate watermark for Restoration
Use the extract watermark for Restoration
09/18 H. Wang, A.T.S. Ho and X. Zhao
Proposed Watermarking Method
Linear Regression Analysis:
10/18 H. Wang, A.T.S. Ho and X. Zhao
Proposed Watermarking Method
11/18 H. Wang, A.T.S. Ho and X. Zhao
Proposed Watermarking Method
Probability Distribution
Mean Pixel Value AC Coefficient
[12]. Li, G., Pei, S., Chen, G., Cao, W.,Wu, B.: A Self-embedded Watermarking Scheme Based on Relationship Function of Corresponding Inter-blocks DCT Coefficient. In: CSCWD 2009, pp. 107-112 (2009)
Li et al.’s method[12] for image restoration
12/18 H. Wang, A.T.S. Ho and X. Zhao
Experimental Results
Original Image Watermarked Image Modified&Attacked Image
Restored without Attack Authenticated Image Restored with JPEG 75 Attack
13/18 H. Wang, A.T.S. Ho and X. Zhao
• Test image:
greyscale images
size:512x512 pixels
• Payload:
6bits/ 8*8 block for authentication
4 decimals/ 8*8 block for recovery
• Imperceptibility
PSNR: 37.61 dB
• False Rate of Authentication
• Robustness of Restoration Scheme
Experimental Results
QF=85
QF=75
QF=65
14/18 H. Wang, A.T.S. Ho and X. Zhao
Imperceptibility
Quality of Recovered Image
Experimental Results
[12]. Li, G., Pei, S., Chen, G., Cao, W.,Wu, B.: A Self-embedded Watermarking Scheme Based on Relationship Function of Corresponding Inter-blocks DCT Coefficient. In: CSCWD 2009, pp. 107-112 (2009) [13]. Chamlawi, R., Khan, A., Idris, A.: Wavelet based image authentication and recovery. Journal of Computer Science and Technology, vol. 22(6), pp. 795-804 (2007)
15/18 H. Wang, A.T.S. Ho and X. Zhao
Experimental Results
QF=95 QF=85 QF=75 QF=65
Our Methods:
Robu
stn
ess o
f Resto
ratio
n S
chem
e
Li’s [4]:
Chamlawi’s [5]:
JPEG Compression
16/18 H. Wang, A.T.S. Ho and X. Zhao
Conclusion and Future Work
Conclusion
A novel semi-fragile watermarking scheme for:
-tampered area localisation
-self-restoration
Approaches utilised to analyse the feasibility of proposed method:
- Linear Regression
- Probability distribution
Result of data analysis:
-The imperceptibility of our watermarked image: 37.61 dB
-PSNR of restored image on average: 24.71 dB
-PSNR of restored image after JPEG compression:
2.5 dB higher than the other two methods
17/18 H. Wang, A.T.S. Ho and X. Zhao
Conclusion and Future Work
Future Work
- test robustness to some other non-malicious attack, such as
noise and spatial filtering
- investigation new method by merging of watermarks for
authentication and self-restoration together
Hui WANG 26BB02
Computing Department University of Surrey Guildford, UK
GU2 7XH 0044-07411098590
18/18 H. Wang, A.T.S. Ho and X. Zhao