Improved Visual Cryptography Scheme using Hopfield for Halftone Images

Visual cryptography is an emerging cryptography technology that uses the characteristics of human vision to decrypt the encrypted images. Watermarking is a method in which an image or pattern is put on paper in the form of various shades of lightness/darkness especially when viewed by transmitted light. Digital watermarking where computer-aided information is used in the hiding information is one of the most popular forms of watermarking. From security point of view it also ensures that hackers cannot perceive any clues about a secret image from individual cover images. In this paper proposed a digital watermarking scheme for halftone images in Visual Cryptography. By using this technique watermark is embedded in the synapse of cover image. The quality of watermarked image is same as that of cover image. In this research two images are taken and results for various parameters are compared. The experimental results show that the scheme is robust and transparent against various watermarking attack.