A Secure Image Watermarking Using Visual Cryptography

Abstract

In this paper we proposed a secure image watermarking algorithm for digital image using the visual cryptography. The proposed algorithm operates in discrete cosine transform (DCT) and discrete fractional random transform (DFRNT) domain which is characterized by fractional order α and random seed β. In the watermark embedding process of the proposed algorithm some blocks of a cover object is selected randomly, and they are transformed to DFRNT domain. The watermark is generated by the visual cryptography and embedded into the DCT coefficient of the DFRNTed block. The watermark extraction process is the reverse process of embedding process. The proposed watermarking algorithm has high security by the visual cryptography and the randomness of discrete fractional random transform. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against JPEG compression, common image processing distortions.