High capacity multi-scale image sharing scheme by combining visual cryptography with data hiding

In this paper we propose a multi-scale image sharing scheme to hide multiple images to two meaningful sharing images. The proposed method combines conventional 2-out-of-2 visual cryptography with data hiding technique. The overall effort of the proposed scheme is the achievement of decrypting/extracting multiple secret images and reference images from sharing images at different scale-levels. Moreover, it is not only applied to monochromatic images but also color halftone images. The experiment results will demonstrate that the proposed scheme indeed increases more capacity of hidden images than the conventional 2-out-of-2 visual cryptography does.