Proceedings ArticleDOI
Registration-tolerant extended visual cryptography
Mizuho Nakajima,Yasushi Yamaguchi +1 more
- Vol. 5007, pp 473-484
TLDR
This new approach tolerates registration error for the third image and eases the difficulty, by adopting concentric-circular subpixel arrangement and continuous grayscale subpixel values, and becomes considerably robust to the registration error.Abstract:
Extended Visual Cryptography is a method which
encodes a number of images so that when the images are superimposed, the hidden image appears without a trace of original images. The decryption is done directly by human eyes without cryptographic calculations. The proposing system takes three pictures as input and generates two images which correspond to two of the input pictures. The third picture is perceived by superimposing the two output images.
Previous methods are based on halftoning and Boolean operations.
Transparency values must be quantized before encryption, and a pixel is halftoned by a fixed numbers of completely transparent and opaque
subpixels. Then a transparency of the superimposed pixel is controlled by changing the subpixel arrangements of the two output pixels. Since the subpixel arrangement is basically random, a tradeoff exists that to express the more graylevels, each subpixel must become the smaller, making it the more difficult to superimpose by hand.
Our new approach tolerates registration error for the third image and
eases the difficulty, by adopting concentric-circular subpixel
arrangement and continuous grayscale subpixel values. The system
becomes considerably robust to the registration error. Also, it
achieves quality improvement for all three images, by explicitly dealing with continuous graylevels.read more
Citations
More filters
Journal ArticleDOI
On general construction for extended visual cryptography schemes
Daoshun Wang,Feng Yi,Xiaobo Li +2 more
TL;DR: This paper presents a general construction method for single or multiple binary/grayscale/color secret images using matrix extension utilizing meaningful shares, which is more general than most existing schemes in terms of the secret/share image types.
References
More filters
Journal ArticleDOI
Visual Cryptography for General Access Structures
TL;DR: This paper examines graph-based access structures, i.e., access structures in which any qualified set of participants contains at least an edge of a given graph whose vertices represent the participants of the scheme, and provides a novel technique for realizing threshold visual cryptography schemes.
Journal ArticleDOI
Extended capabilities for visual cryptography
TL;DR: An extended visual cryptography scheme, for an access structure (ΓQual,ΓForb) on a set of n participants, is a technique to encode n images in such a way that when the authors stack together the transparencies associated to participants in any set X∈�Qual they get the secret message with no trace of the original images, but any X∈Γ forb has no information on the shared image.
Journal ArticleDOI
Constructions and Properties of k out of nVisual Secret Sharing Schemes
TL;DR: Two general k out of n constructions that are related to those of maximum size arcs or MDS codes and the notion of coloured visual secret sharing schemes is introduced and a general construction is given.
Book ChapterDOI
New Results on Visual Cryptography
TL;DR: A new principle of construction for k out of n secret sharing schemes is presented which is easy to apply and in most cases gives much better results than the former principlcs.
Proceedings Article
Extended visual cryptography for natural images
TL;DR: This paper presents a system which takes three pictures as an input and generates two images which correspond to two of the three input pictures, which are reconstructed by printing the two output images onto transparencies and stacking them together.
Related Papers (5)
Construction of color Extended Visual Cryptographic scheme using Back Propagation Network for color images
J. Ida Christy,V. Seenivasagam +1 more
An image composition algorithm for handling global visual effects
M. Shahid Farid,Arif Mahmood +1 more