A Robust Digital Image Watermarking Using Dwt -Pca

Abstract

A comprehensive approach for watermarking is introduced in this system, and a hybrid digital watermarking scheme based on Discrete Wavelet Transform (DWT) and Principal Component Analysis (PCA) is used. There are some watermarking techniques like DCT, DWT, and DWT-SVD, but there is disadvantage in the watermarking to withstand attacks. Hence the new digital image watermarking algorithm is proposed which provide robust watermarking with minimal amount of distortion in case of attacks. DWT offers scalability and PCA helps in reducing correlation among the wavelet coefficients obtained from wavelet decomposition of each block thereby dispersing the watermark bits into the uncorrelated coefficient. Peak signal ratio is used to measure invisibility whereas similarity between two images by normalized correlation coefficient test the transparency and robustness against various attacks like cropping, noise, rotation, filtering etc. The proposedsystem should provide recoverable watermark without any reasonable amount of distortion even in case of attacks