Halftone visual cryptography with color shares

Halftone visual cryptography (HVC) is a visual sharing scheme where a secret image is encoded into halftone shares taking meaningful visual information. In this paper, a HVC construction method is proposed that can encode a secret halftone image into color halftone shares. The secret image is concurrently embedded into color halftone shares while these shares are halftoned by constrained vector error diffusion. The proposed method is able to generate halftone shares showing natural color images with high image quality.