1 Data Hiding Watermarking for Halftone Images Ming Sun Fu, Student Member, IEEE, and Oscar C. Au,...
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1 Data Hiding Watermarking for Halftone Images Ming Sun Fu, Student Member, IEEE, and Oscar C. Au, Senior Member, IEEE, IEEE TRANSACTIONS ON IMAGE PROCESSING, Vol. 11, No. 4, Apr. 2002, pp. 477 -484
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Transcript of 1 Data Hiding Watermarking for Halftone Images Ming Sun Fu, Student Member, IEEE, and Oscar C. Au,...
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Data Hiding Watermarking for Halftone Images
Ming Sun Fu, Student Member, IEEE, and Oscar C. Au, Senior Member, IEEE, IEEE TRANSACTIONS ON IMAGE PROCESSING, Vol. 11, No. 4, Apr. 2002, pp. 477 -484
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Outline
Introduction
Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)Data Hiding with Original Multitone Image (DHED, MDHED)Conclusions
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IntroductionHalftone images
Error diffusion
Jarvis kernel and Steinberg kernel
JARVIS AND STEINBERG KERNELS FOR ERROR DIFFUSION
7
153
3
3 3
3
11 5
5 57
7 5
Jarvis Kernel Steinberg Kernel
4
Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding Self Toggling(DHST) use seed generate a set of N pseudo-random loc
ation. embedded 0 or 1 ( 1 bit ) simple & error correction coding “salt-and-pepper” noise intensity being about 128 location [ 10, 752, 950, . . . ]hiding bit stream [ 0 1 0 . . .
halftone imageEx. 150 * 150
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Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding Pair Toggling(DHPT) slave pixel is chosen randomly. two errors are introduced instead of one complexity is slightly larger than DHST fewer “salt-and-pepper” noise M=
000
000
000 1
001
101
100
IF hiding 1
001
111
100
master pixel
001
111
100
choose any oneadjacency "1"
001
011
100
slave pixel
5*04*1
4*05*1
5*04*1
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Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding by Smart Pair Toggling(DHSPT) Candidate is Min [conafter(m,n)] Define
),,()(),(8
10
i
ixxfiwnmcon
0
1),( where
yx
yxyxf
2
2 x0
2
2
1 1
x0
1 1
7
Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
Data Hiding by Smart Pair Toggling(DHSPT)
Ex. before after
1+2+2=5 2+1+2+1+1=7
12)(
)],( ),()[(),(),(
8
1
0
8
10
i
ii
iafterbefore
iw
xxfxxfiwnmconnmcon
1 0 0
0 X0=1
1
0 1 0
+1 0 0
0 X0=0
1
0 1 0
- = 12
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Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
W( f(X0, Xmaster) + f(X0, Xmaster)) = 2
before after
vertical or horizontal master w(i) = 2
conbefore(m, n) + conafter(m, n) = 10
other master w(i) = 1
conbefore(m, n) + conafter(m, n) = 11
Xmaster=1 X0=0
Xmaster=1 X0=1
-
-
9
Data Hiding without Original Multitone Image (DHST, DHPT, DHSPT)
conbefore=1+2+2+1+2=8 conafter=11-8=3
n) (m,
before11
n) (m, before
10 n) (m,
after
DHSPT
DHSPT
DHSPT
con -
con -con
otherwise
orizontalvertical/h
1 0 1 0
1 1 1 0
1 0 0 0
1 0 0 1
conbefore=2+2+1=5
conafter=10-5=5
conbefore=0
conafter=10-0=10 1 0 1 0
1 0 1 0
1 0 1 0
1 0 0 1
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Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion
100100140
10090120
120110160
100100140
10090120
120110160
Threshold=128
JARVIS AND STEINBERG KERNELS FOR ERROR DIFFUSION
7
153
3
3 3
3
11 5
5 57
7 5
Jarvis Kernel Steinberg Kernel
halftone bit = 1error = 160-255 = -95
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Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion
110+(7/16)*(-95)=68
100100140
10090120
120110160
100100145
1008490
12068255
90+(1/16)*(-95)=84
120+(5/16)*(-95)=90
255 --> 160
120+(7/16)*(68)=150
100100145
104105103
1500255
100+(1/16)*(68)=104
84+(5/16)*(68) =105
90+(3/16)*(68) =103halftone bit = 0error = 68-0=68
compute left --> right top --> downuntil end
0 --> 68
halftone bit = 1error = 160-255 = -95
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Data Hiding with Original Multitone Image (DHED, MDHED)
Error diffusion
))1,(7)1)(1(3),1(5)1)(1((16
1),( jiejiejiejiejia
),(),(),( jiajixjif
otherwise
Tjififjiy
255
),(0),(
),(),(),( jiyjifjie
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Data Hiding with Original Multitone Image (DHED, MDHED)
Data Hiding Error Diffusion
120+(7/16)*(-187)=38
100100145
882655
3868255
100+(1/16)*(-187)=88
84+(5/16)*(-187) =26
90+(3/16)*(-187) =55
original Error=68-0=68 Halftone bit=0If Hidden data = 1
chang Error =68-255 =-187 Halftone bit=1
Errordiffusion
120+(7/16)*(68)=150
100100145
104105103
15068255
100+(1/16)*(68)=104
84+(5/16)*(68) =105
90+(3/16)*(68) =103
original Error=68-0=68 Halftone bit=0If Hidden data = 0
do not chang Error=68 Halftone bit=0
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Data Hiding with Original Multitone Image (DHED, MDHED)
Modified Data Hiding Error Diffusion
),(),(),( jiyjixe jiguess
),(),(),( jiyjife jiorig
otherwise
Tjifjiy
255
),(0),(
)1,1(),1()1,1(
)1,(),()1,(
)11(),1()1,1(
jixjixjix
jixjixjix
jixjixjix
)1,1(),1()1,1(
)1,(),()1,(
)11(),1()1,1(
jifjifjif
jifjifjif
jifjifjif
E rror for p ast, (1E rror for p ast, (1 -- ) * ) * ee guessguess (( ii , , jj ))
E rror for fu tu re, (E rror for fu tu re, ( ) * ) * ee guessguess (( ii , , jj ))
S elect S elect , 0, 0 1 , for fu tu re p ixels, (11 , for fu tu re p ixels, (1 -- ) for p aste p ixels) for p aste p ixels
15
Conclusions
4096/(512*512)=1.6 %
28900/(512*512)=11 %
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Conclusions隱藏少量資料時不見得取得優勢
隱藏多量資料時 good choice
28900/4096 = 7 倍
Steinberg 皆優於 Jarvis kernel
