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An Image Fragile Watermark Scheme Based on Chaotic Image Pattern

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An Image Fragile Watermark Scheme Based on Chaotic Image Pattern Powered By Docstoc
					An Image Fragile Watermark
Scheme Based on Chaotic Image
Pattern and Pixel-pairs

 Source: Applied Mathematics and Computation, article
         in press, 2006
 Author: Shao-Hui Liu, Hong-Xun Yao, Wen Gao and Yong-
         Liang Liu
 Speaker: Yung-Chen Chou
 Date: Nov. 16, 2006
Outline
   Introduction
   Two typical attacks
   The watermarking algorithm
   Experiments
   Conclusions



                  Yung-Chen Chou   2
Introduction
   Robust watermarking
       Copyright protection
       Anti general image processing
   Fragile watermarking
       Semi fragile  soft authentication
       Complete fragile  hard authentication



                      Yung-Chen Chou             3
Introduction (cont.)
   Walton’s method (1995)
                    4210=001010102

                                     Check sum=1


           H
                           001010112

   Yeung-Mintzer scheme (1997)
                                   0    0
                                   1    0
                                   2    1
                                   3    1
               42                  :    :
                                        1     ?
                                  41
                                  42    0     =
                                        :
       H                           :
                                 255    1
                                       LUT         W
                            Yung-Chen Chou             4
 Two attacks
     Vector quantization attack (Wong and Memon, 2000)

Hw1



Hw2                    MSN                MSN


                         H                 HCF



Hwn
                         Yung-Chen Chou                   5
     Two attacks (cont.)
        Oracle attack
                                                    …


                                                   SP
Hw           0
             1
             2

              :

            255          Oracle
                                              …


                                              SF


                             Yung-Chen Chou             6
The watermarking algorithm
   Chaotic image pattern
       Chaos theory (Edward Lorenz, 1963)

    x(n  1)  g  ( x(n))    x(n)  (1  x(n))
    g     x  (1  x)
     [1,4]



                        Yung-Chen Chou               7
     The watermarking algorithm
     (cont.) (Chaotic image pattern)
Example:
μ=3.89                                       μ=3.89
x(1) = 0.4567  104                          x(1) = 0.4568  104
x(2) = 3.89*0.4567*(1-0.4567)=0.9652 253    x(2) = 3.89*0.4568*(1-0.4568)=0.9652 253
x(3)=0.130637  8                            x(3)=0.130515  8
x(4)=0.441791  99                           x(4)=0.441441  99
x(5)=0.959319  251                          x(5)=0.95916  251             99.26% pixels have
x(6)=0.15181  14                            x(6)=0.152378  14                different values
x(7)=0.50089  117                           x(7)=0.502428  117
x(8)=0.972497  255                          x(8)=0.972477  255
x(9)=0.104045  0                            x(9)=0.104117  0
x(10)=0.362623  76                          x(10)=0.362848  76
x(11)=0.899086  233                         x(11)=0.899326  234
x(12)=0.352941  73                          x(12)=0.352195  73
x(13)=0.888373  230                         x(13)=0.887518  230
x(14)=0.385757  83                          x(14)=0.388337  83
x(15)=0.921729  240                         x(15)=0.923997  241
x(16)=0.280641  52                          x(16)=0.273181  50
x(17)=0.78532  200                          x(17)=0.772372  196
x(18)=0.655825  162                         x(18)=0.683914  170
x(19)=0.878045  227                         x(19)=0.840924  216
x(20)=0.41655  92                           x(20)=0.520369  122
…                                            …
                                            Yung-Chen Chou                                        8
              The watermarking algorithm
              (cont.) (Embedding)
155    148    161    143    163                  163   180    145   178   161                            162    180     144     178     160
148    168    130    180    126                  143   130    158   145   161                            142    130     158     144     160
151    158    145    163    143                  168   151    148   148   155                            168    150     148     148     154
145    178    118    194    112                  194   112    112   143   194   Set LSB bitplane         194    112     112     142     194
                                   HP=PT(H,K1)                                  of HP as 0
161    130    188    112    194                  188   126    163   118   130                            188    126     162     118     130

              H                                               HP                                                        HPNLSB


 104    253    8      99     251                 162   180    144   178   160
                                                                                                   58      73     136     79      91
 14     117    255    0      76                  142   130    158   144   160
                                                                                                   128     13     97      144     84
 233    73     230    83     240                 168   150    148   148   154
                                                                                                   65      77     82      65      86
 52     200    162    227    92                  194   112    112   142   194
                                                                                                   142     88     50      85      102
 45     76     56     160    104                 188   126    162   118   130
                                                                                                   143     50     106     42      26

               RCP                                           HPNLSB                                               D


                                                                Yung-Chen Chou                                                                9
                    The watermarking algorithm
                    (cont.) (Embedding)
    58        73    136   79    91            0   1     0   1   1                0    1    1     1   0                 0    0    1     0     1

    128       13    97    144   84            1   0     1   0   1                0    1    0     0   1                 1    1    1     0     0

    65        77    82    65    86            1   1     1   1   1    ⊕           0    1    1     1   0                 1    0    0     0     1
    142       88    50    85    102           0   1     0   1   1                0    1    0     0   1                 0    0    0     1     0
    143       50    106   42    26            0   0     1   0   1                0    1    1     1   0                 0    1    0     1     1

                    D                             QD                                       WP

0        15    32         64                  128                                                          255                             Replace LSB
                                                                                                                                           bitplane of HPNLSB
          Set A  0
          Set B  1                                                                                              162       180       144     178   160
                          155   148   160   143   162               162    180       145       178   161
                                                                                                                 142       130       158     144   160
                          148   169   131   180   127               143    131       159       144   160
                                                                                                                 168       150       148     148   154
                          150   159   145   162   143               169    150       148       148   155
                                                                                                                 194       112       112     142   194
                          144   178   119   192   112               194    112       112       143   194
                                                                                                                 188       126       162     118   130
                          161   131   188   112   194               188    127       162       119   131
                                                                                                                                 HPNLSB
                                     HW                                   Yung-Chen Chou                                                                 10
            The watermarking algorithm
            (cont.) (Extracting)
                                                                                                 0   0     1    0    1

155   148   160       143   162                     162   180    145   178    161                1   1     1    0    0

148   169   131       180   127                     143   131    159   144    160                1   0     0    0    1

150   159   145       162   143                     169   150    148   148    155                0   0     0    1    0

                                                    194   112    112   143    194                0   1     0    1    1
144   178   119       192   112

161   131   188       112   194   HWP=PT(HW,K1)     188   127    162   119    131
                                                                                           162       180       144       178   160
        HW                                                       HWP                       142       130       158       144   160
                                                                                           168       150       148       148   154
        0   1     1    1    0
                                            ⊕                                              194       112       112       142   194
        0   1     0    0    1                                                              188       126       162       118   130
                                                           58     73    136    79    91
        0   1     1    1    0
                                                           128    13    97     144   84
        0   1     0    0    1       0   1   0   1   1                                      104       253       8         99    251
                                                           65     77    82     65    86
        0   1     1    1    0       1   0   1   0   1                                      14        117       255       0     76
                                                           142    88    50     85    102
                WE                  1   1   1   1   1      143    50    106    42    26    233       73        230       83    240
                                    0   1   0   1   1                                      52        200       162       227   92
                                    0   0   1   0   1                                      45        76        56        160   104

                                                                                                               RCP
                                                                 Yung-Chen Chou                                                      11
Experiments



    c         d




                  Yung-Chen Chou   12
Experiments (cont.)




            Yung-Chen Chou   13
Conclusions
   Chaotic map and permutation transform
    are used to improve the security.
   The method can exactly detect the
    tampered areas on the watermarked
    image.




                  Yung-Chen Chou        14

				
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