1 Adaptive Data Hiding in Palette images by Color Ordering and Mapping With Security Protection...
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Transcript of 1 Adaptive Data Hiding in Palette images by Color Ordering and Mapping With Security Protection...
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Adaptive Data Hiding in Palette images by Color Ordering and Mapping With Security
ProtectionAuthors: Chih-Hsuan Tzeng, Zhi-Fang Yang, and Wen-Hsiang TsaiSource: IEEE Transactions On Communications, Vol. 52, No. 5, May 2004, pp. 791-800.
Adviser : Wen-Chung Kuo
Jiin -Chiou Cheng
Repoter : Wei-De Hsu
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Outline
• Introduction • The proposed method
– Color-ordering relationship– Color-mapping function– Data-embedding process– Data-extraction process
• Experimental results• Conclusions
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Introduction
• Gifshuffle– The idea is to permute the colors in the
palette of an image in a specific order in accordance with the secret data. (256!)
indexes colors
0 0 0 0
1 0 255 0
2 255 0 0
3 0 0 255
Ex: 4!
[6] M. Kwan. (1998) GIF Colormap Steganography. [Online]. Available: http://www.darkside.com.au/gifshuffle/
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Introduction
(a) The original image. (b) Replacement by the closet color.
(c) Replacement by the neighboring color.
Three colors c1, c2, c3, with RGB values (0, 174, 239), (57, 181, 74), and (236, 0, 140) are contained in the sample images.
[12] J. Fridrich and R. Du, “Secure steganographic methods for palette images,” in Proc. 3rd Int. Workshop Information Hiding, Dresden, Germany, 1999, pp. 47–60.
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Color-ordering relationship
c1 c2 c3
c4
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Proposed data-embedding process
12 12 12
12 12
12 12 16
10 10
12 12 12
12 60
12 16 17
10 18
00
26
148
48
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Proposed data-embedding process
otherwise ,embeddable-non
and ,embeddable dc TTx
12 12 12
12 12
12 12 12
12 6000
148
10 ,2 dc TT
Non-embeddable
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Proposed data-embedding process
otherwise ,embeddable-non
and ,embeddable dc TTx
12 12 16
10 10
12 16 17
10 6026
48
10 ,2 dc TT
embeddable
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Color-mapping function
otherwise.
if
if
if
if
0,
1,
0,
1,
0,
),...,,('4
'3
'3
'2
'2
'1
'1
'4
'1
ccc
ccc
ccc
cc
cccfcm
'4
'3
'2
'1 cccc
'3c
'1c
'4c
'2c
c
c1 c2 c3
c4
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Color-mapping function
12'3 c 17'
1 c
10'4 c
otherwise.
if
if
if
if
0,
1,
0,
1,
0,
),...,,('4
'3
'3
'2
'2
'1
'1
'4
'1
ccc
ccc
ccc
cc
cccfcm
48
36
16'2 c
18c
12'3 c 17'
1 c
10'4 c
16'2 c
16c
Hiding 0 Hiding 1
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Data-extraction process
otherwise.
if
if
if
if
0,
1,
0,
1,
0,
),...,,('4
'3
'3
'2
'2
'1
'1
'4
'1
ccc
ccc
ccc
cc
cccfcm
36
12'3 c 17'
1 c
10'4 c
16'2 c
16c
12
Experimental results
colors). 256( 256256 15640 bits/44.8dB
10 ,2 dc TT
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Experimental results
colors). 256( 300213 2003 bits/43.7dB
10 ,2 dc TT
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Experimental results
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Conclusions
• The experimental results show that secret data can be embedded and extracted successfully without producing visual artifacts in the cover image.
• A good balance between stego-image quality and data-embedding capacity can be achieved.