A halftone visual cryptography schema using ordered dither
Liuping Feng, Dong-Sheng Cong, Huaqun Liu, Meng-Min Wang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2014
Visual cryptography is a cryptographic technique which allows visual information to be encrypted in such a way that the decryption can be performed by the human visual system, without the aid of computers. This paper proposes a schema of information hiding within the method of visual cryptography. The gray image is changed into two halftone images via the different dither matrixes respectively, and the secret binary pixels are encoded into shares. The secret information can be restored by stacking the different shared halftone images together. Simulation results show that the secret binary image can be decoded efficiently.