1. A Digital Watermarking Scheme Based on Singular Value Decomposition
Speaker: Prof. Chin-Chen Chang

2. Outline Digital Watermarking System Watermarking Category
SVD (Singular Value Decomposition)
Proposed Scheme
Experimental Results
Conclusions
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3. Digital Watermarking System
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4. Watermarking Category- Robustness
Three categories
Robust watermarking schemes
Fragile watermarking schemes
Semi-fragile watermarking schemes 
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5. Watermarking Category- embedding approach
Spatial domain-based scheme
Low computational complexity
Lower robustness
Frequency domain-based scheme
Need more computation
Provide better robustness
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6.  SVD-based schemes Similar to frequency domain based scheme
SVD can be considered as a transformation 
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7. SVD Singular Value Decomposition Assume that rank of A is r.
U and V are N x N orthogonal matrices, U x UT=I, V x VT=I
S is an N x N diagonal matrix, σ1 ≥σ2 ≥…≥σr ≥σr+1 =…=σN =0
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8. Proposed Scheme (1/3) 4 4
Binary watermarking image
One bit needs to be embedded in
three different blocks
Original image
Use a one way hash function
based on Rabin’s scheme to
decide the embedding block
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9. Proposed Scheme (2/3) Embedding process Wi = 1, δ = 20 SVD 23.2527 U x
x VT
δxWi
3.2527
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10. Proposed Scheme (3/3) Extracting process δ/2 = 10 SVD U x x VT
= > 10
W’2=0
W’2=1
The same
process
W’1=1
W’1+W’2+W’3 > 2
W’=1
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11. Experimental Results (1/7)
Seven 512x512 gray-scale test images and one 64x64 binary image
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12. Two measurements PSNR BCR Peak Signal-to-Noise Ratio
Bit Correction Ratio
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13. Experimental Results (2/7)
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14. Bit Correction Ratio = 100%
Original image
Watermarked image
(PSNR = 35.37dB)
Extracted watermark
Bit Correction Ratio = 100%
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15. Experimental Results (3/7)
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16. after JPEG compressing (PSNR = 35.87dB) Extracted watermark
Watermarked image
after JPEG compressing
(PSNR = 35.87dB)
Extracted watermark
(Bit Correction Ratio = 87.92%)
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17. Experimental Results (4/7)
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18. after sharpening process (PSNR = 29.23dB) Extracted watermark
Watermarked image
after sharpening process
(PSNR = 29.23dB)
Extracted watermark
(Bit Correction Ratio = 95.73%)
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19. Experimental Results (5/7)
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20. after blurring process (PSNR = 35.60dB) Extracted watermark
Watermarked image
after blurring process
(PSNR = 35.60dB)
Extracted watermark
(Bit Correction Ratio = 92.41%)
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21. Experimental Results (6/7)
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22. after cropping process (PSNR = 35.60dB) Extracted watermark
Watermarked image
after cropping process
(PSNR = 35.60dB)
Extracted watermark
(Bit Correction Ratio = 90.19%)
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23. Experimental Results (7/7)
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24. (Bit Correction Ratio = 89.28%)
Watermarked image
after adding noise
(PSNR = 32.54dB)
Extracted watermark
(Bit Correction Ratio = 89.28%)
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25. Comparisons with other schemes
Items
Hwang et al.
Liu and Tan
Chandra (Global-based)
Chandra (Block-based)
Proposed scheme
Processing domain
Spatial
SVD
Extracting watermarks with original image No
Yes
Storing some matrices to extract watermark
Robustness
Low
High
Embedding quality
Very high
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26. Conclusion SVD-based watermarking scheme for binary logo
The proposed scheme has good efficiency
The PSNR values of the watermarked images are all greater than 31 dB
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