DefinePK

Abstract

A novel technique for reversible digital image watermarking which is robust against image manipulations and transformations is proposed in this paper. An extended variant of Discrete Wavelet Transform (DWT) is utilized for the decomposition of images. In Extended Discrete Wavelet Transform (EDWT), sampling processes are avoided form DWT during analysis step and synthesis step respectively. EDWT is applied to watermark image as well as cover image results in shift invariance and accurate extraction of watermark. Singular Value Decomposition (SVD) is then applied to sub-bands that have low frequency of occurrence in the image. Watermarking pixels are embedded inside the wavelet coefficients of unmodified host image and this will overcome security issues. This method is robust against various types of noises and attacks occur while transferring the image though a channel. Performance of the proposed method is compared with the performance of DWT-SVD watermarking scheme. The performance is compared in terms of correlation and PSNR.