Visual secret sharing schemes for color images using halftoning via direct binary search

This paper proposes a method of encoding a color image into n meaningful halftone shares using the scheme of halftone visual cryptography. The proposed method can encode the secret pixels into the shares via direct binary search (DBS) halftoning method for color images. The error between the halftone shares and the continuous-tone images are minimized with respect to a human visual system (HVS) model. Simulation results show that the proposed method can improve halftone image quality for the enclosed shares compared with previous techniques.