A Kind of Visual Cryptography Scheme for Color Images Based on Halftone Technique

This paper proposes a new secret visual cryptography scheme for color images based on halftone technique. Firstly, a chromatic image is decomposed into three monochromatic images in tones of cyan, magenta and yellow. Secondly, these three images are transformed into binary images by halftone technique. Finally, the traditional binary secret sharing scheme is used to get the sharing images. This scheme provides a more efficient way to hide natural images in different shares. Furthermore, the size of the shares does not vary when the number of colors appearing in the secret image differs.