An Improved and Robust DCT Based Digital Image Watermarking Scheme

Abstract

The need for displaying one„s own multimedia content on the internet is increasing day by day. With the exponential growth of internet and high speed networks operating through out the world it‟s a challenging task to protect copyright of an individual‟s creation. Digital watermarking provides a viable solution to protect copyright and authenticate the ownership of an intellectual property. In this paper we propose a new DCT based additive watermarking scheme which provides higher resistance to image processing attacks mainly JPEG compression. In our approach the watermark is embedded in the mid frequency band of the DCT blocks only in the sub band which is carrying low frequency components and the high frequency sub band components remain untouched. General Terms Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT), Discrete Image watermarking, Joint Photographic Experts Group (JPEG), JPEG Quality Factor (Q), Peak Signal to Noise Ratio (PSNR)