Abstract: In this paper Visual cryptography scheme is a cryptographic technique which allows the information which is visual such as printed text, handwritten notes and images to be encrypted in such a way that its decryption does not require a computer, it can be done by the human visual system. In extended visual cryptography, the meaningful cover images are added to the share images, which provides an opportunity to integrate visual cryptography and biometric security techniques. In this paper, a method has been proposed by using the extended visual cryptography scheme for processing halftone images that improves the quality of the share images and the recovered secret image for which the size of the share images and the recovered image can be preserved as same as that of the original halftone secret image.

Keywords: Visual cryptography, OR operation, subpixels, BBR.