A (2,2) secret sharing scheme for visual cryptography without Pixel Expansion

摘要

Secret sharing scheme denes a method by which a secret image can be distributed between a group of participants, whereby each participant is collected a piece of the secret. This piece of the secret is known as a share. The original secret image can be only be recovered when a sufficient number of shares are combined together. In this paper, a (2,2) VCS has been proposed, where two adjacent pixels are taken together as the one time input for generation of shares. The simulation shows that after comparing the proposed method with conventional VCS, the proposed method has non-distortion (with respect to Aspect Ratio and Pixel Expansion) and the visual quality of reconstructed image is better (with respect to PSNR).