Extended visual cryptography for color images using coding tables

Abstract

Visual cryptography (VC) schemes encrypt a secret image into two or more cover images, called shares. The secret image can be reconstructed by stacking the shares together, with no complex cryptographic calculations. This paper proposes a new VC scheme for color images. The shares generated are similar to the cover images, thereby reducing the suspicion of data encryption. The proposed scheme makes use of Jarvis error filter, a key table and specialized tables for coding. High visual quality is achieved as up to 50 percent of the secret image can be recovered.