Visual Cryptography based Grayscale Image Watermarking in DWT domain

Abstract

Watermarking is a technique to protect the copyrights of digital media like image, audio, video, etc. Visual Cryptography (VC) is a scheme for hiding information in still images. The Visual Cryptography Scheme splits the secret image into unintelligible images, these images are called shares. The shares are distributed to ‘n’ participants. Any ‘k’ shares out of ‘n’ reveal the secret image and less than ‘k’ shares recover no information about secret. Amalgamating Visual cryptography with watermarking yields the best solution for resolving image ownership disputes and detection of infringements of copyrights. In this paper, (2,2) VC scheme is employed, one of the shares is embedded in the low frequency domain of DWT and the other share is registered with the Trusted Authority(TA). The secret image is obtained by performing XOR operation on the two shares. The experimental results revealed that the proposed scheme can not only prove the ownership of image but also withstand various image processing attacks.