Docstoc

Digital Watermarking Implementation

Document Sample
Digital Watermarking Implementation Powered By Docstoc
					             Digital Watermarking
               Implementation


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


04/25/2002                            1
             Our Digital World




04/25/2002                       2
              Digital Flaws
 Illegal Copying
 Falsification
 No Copyright
  Protection
 No Ownership
  Identification




04/25/2002                    3
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
04/25/2002                                             4
           How Digital Watermarking
                   Works?
                         Attack or Distortion
   Watermark Insertion                          Watermark Detection
                               Channel




Watermark
                                                         Watermark
Original Image
      Key (Code)
     04/25/2002                                                5
             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).


04/25/2002                                  6
               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))
  04/25/2002                                                     7
Marked         Watermark Detection
                                                    Extracted
               DCT                                  Watermark
                                   -


               DCT
                                                     Similar?

Original                               Original
                                       Watermark
                Similarity Function
                sim(X,X*) = dot(X*,X)/sqrt(X*,X*)
  04/25/2002    X* = Extracted      X = Original          8
                    Results
             1) Watermarked Image




04/25/2002                          9
        2) Low Pass Filter Image




04/25/2002                         10
             3) Median Filter Image




04/25/2002                            11
             4) Noise Image




04/25/2002                    12
   5) 15% Quality JPEG Image




04/25/2002                     13
        Final Stage (DSP Board)
                     TMS320C6701 (Texas
                      Instruments)
                     Floating Point
                      Processor
                     Graphics/Imaging
                       -Image Processing
                       -Image Enhancement
                       -Image Compression
                       -Image Transmission
04/25/2002
                       -Robot Vision      14
             DSP Goals
 Rewrite codes from Matlab to C Language.
 Test the codes on the DSP Board for
  watermark robustness.




04/25/2002                                   15
             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
04/25/2002                                16

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:8
posted:9/23/2011
language:English
pages:16