Spread Spectrum Digital Watermarking Using Orthogonal Ramanujan Wavelet Transform

This paper aims to explore the embedded watermarking scheme using a spread spectrum based algorithm employing Discrete Wavelet Transform (DWT) and Orthogonal Ramanujan Wavelet Transform (ORWT). We further carry out detailed comparison between the results obtained from the two algorithms for grayscale as well as color images in RGB format. We have also tested the robustness of the watermarking techniques against various channel attacks. We obtain an improvement of upto 12.634% in correlation and upto 5.247% in normalized correlation value for original and recovered watermark in case of grayscale images, using ORWT compared to DWT.