Digital Watermarking Implementation

							             Digital Watermarking
               Implementation


      Presented by: Marco A. Lassus
         Advisor: Manuel Toledo
          Sponsored by: Kodak


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             Our Digital World




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              Digital Flaws
 Illegal Copying
 Falsification
 No Copyright
  Protection
 No Ownership
  Identification




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What is Digital Watermarking?
   Digital Watermarking         The embedding must
    is the embedding of a         not cause serious
    signal(watermark) into        degradation to the
    another signal (image)        original signal




             Original Image   Watermarked Image
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           How Digital Watermarking
                   Works?
                         Attack or Distortion
   Watermark Insertion                          Watermark Detection
                               Channel




Watermark
                                                         Watermark
Original Image
      Key (Code)
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             Research Objectives
 To implement a robust watermarking
  scheme for gray-level digital images
  (Software).
 To implement the software into hardware
  using a DSP Board (Digital Signal
  Processor).


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               Watermark Insertion                        Inverse
               DCT        Determine Significant Regions   DCT




                 Change
       DCT       Matrix to Vector
                                                     Insert
                           +
                                                     Watermark

Random Numbers
                      Cox’s Watermarking Insertion

                     Vi’ = Vi * (1 + a * (Xi + b * Wi))
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Marked         Watermark Detection
                                                    Extracted
               DCT                                  Watermark
                                   -


               DCT
                                                     Similar?

Original                               Original
                                       Watermark
                Similarity Function
                sim(X,X*) = dot(X*,X)/sqrt(X*,X*)
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                    Results
             1) Watermarked Image




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        2) Low Pass Filter Image




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             3) Median Filter Image




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             4) Noise Image




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   5) 15% Quality JPEG Image




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        Final Stage (DSP Board)
                     TMS320C6701 (Texas
                      Instruments)
                     Floating Point
                      Processor
                     Graphics/Imaging
                       -Image Processing
                       -Image Enhancement
                       -Image Compression
                       -Image Transmission
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                       -Robot Vision      14
             DSP Goals
 Rewrite codes from Matlab to C Language.
 Test the codes on the DSP Board for
  watermark robustness.




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             References
 Cox, Kilian, Leighton, and Talal Shamoon,
  “Secure Spread Spectrum Watermarking for
  Multimedia”, IEEE Transactions on Image
  Processing, Vol. 6, No. 12, December 1997
 Podilchuk, C.I., Delp, E.J., “Digital
  Watermarking: Algorithms and
  Applications”, IEEE Signal Processing
  Magazine, July 2001, Volume 18 Number 4
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