Visual Cryptography Based on Void-And-Cluster Halftoning Technique

In this paper, visual cryptography for halftone images is proposed, which uses threshold arrays generated by a void-and-cluster method. The proposed halftone visual cryptography (HFC) using threshold arrays shows great flexibility for a combination of share images in order to decode a secret image. Moreover, it also achieves high quality share images, high speed processing and extensibility to (k,n) the visual cryptography of three share image categories, such as (2,3) or (3,3). Simulation results show that all the above features are achieved, while a secret image is clearly decoded, and the secret image cannot be seen on each share image.