Visual cryptography for general access structures
Information and Computation
Visual cryptography for gray-level images by dithering techniques
Pattern Recognition Letters
New visual secret sharing schemes using probabilistic method
Pattern Recognition Letters
Probabilistic Visual Cryptography Schemes
The Computer Journal
Image encryption by random grids
Pattern Recognition
A multiple-level visual secret-sharing scheme without image size expansion
Information Sciences: an International Journal
On the security of a visual cryptography scheme for color images
Pattern Recognition
Visual Cryptography and Secret Image Sharing (Digital Imaging and Computer Vision)
Visual Cryptography and Secret Image Sharing (Digital Imaging and Computer Vision)
ICIAR'06 Proceedings of the Third international conference on Image Analysis and Recognition - Volume Part I
Improving the visual quality of size invariant visual cryptography scheme
Journal of Visual Communication and Image Representation
Hi-index | 0.00 |
Two of the main areas of research in visual cryptography have been on improving the visual quality of the recovered image and in reducing the pixel expansion of the shares. This paper addresses both of these visual cryptography issues. First, a method to enhance the perceived visual quality of the recovered image using various image filtering techniques is presented. In particular, these image filtering techniques are used to enhance the local and global contrasts of a grayscale image. Second, a multi-pixel block size invariant visual cryptography scheme that maintains the relative density of local neighboring pixels is proposed. This method encrypts blocks of pixels based on whether the total number of black pixels within the respective blocks is above or below a certain threshold. In conjunction, these approaches effectively improve on the perceived visual quality of a recovered visual cryptography image.