1
Halftone Visual Cryptography
IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 15, NO. 8, AUGUST 2006, pp. 2441-2
453Zhi Zhou, Gonzalo R. Arce, and Giovanni Di
CrescenzoReporter: Jen-Bang Feng
2
Visual Cryptography
+
+
=
=
3
Visual Cryptography
4
The Proposed Scheme
5
Comparisons
MSEPSNR
2
10
maxlog10
m
QQm
PSNR
2110
21
2
2
10
log10
%50maxmin
maxlog10
EX.Block size: 4*4m = 2PSNR = 9.03
6
Results
(a)(b) (e) extended VC(c) (d) (f) proposed
(2, 3)-threshold
7
Results
8
StackingEDF1 EDF2
watermarkEDF1Lena (gray level)
Error diffusion
Data Hiding in Halftone Images With Noise-Balanced Error DiffusionSoo-Chang Pei, and Jing-Ming GuoIEEE Signal Processing Letters, Vol.10, No.12, December 2003Steganography in halftone images:conjugate error diffusionMing Sun Fu, Oscar C. AuSignal Processing 83 (2003) 2171 – 2178
9Original Lena
NBEDF
Watermark
+Stacking
EDF 1
EDF 2
*
Hybrid Pixel-Based Data Hiding and Block-Based Watermarking for Error-Diffused Halftone ImagesSoo-Chang Pei ( 貝蘇章 ) and Jing-Ming GuoIEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 13, NO. 8, AUGUST 2003, Pages: 867-884.
10
Conclusions and Comments
Applying VC to halftone images
Classify: During process Outside process
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