Efficient Image Watermarking Algorithm Using Non-negative Matrix Factorization and Discrete Wavelet Transform

Abstract

A novel image watermark algorithm based on non-negative matrix factorization (NMF) and discrete wavelet transform (DWT) is proposed in this paper. The processes of watermark embedding include three steps: First the original image is divided to not overlap image blocks and then decomposable coefficients are obtained by three-level DWT in every image blocks. Secondly low frequency decomposition coefficients of block images are selected and then approximately represented as a product of a base matrix and a coefficient matrix using NMF. Finally the feature vector represent original image is obtained by quantizing coefficient matrix, and then the copyright information is embedding by calculating the watermark and feature vector. Simulation results show that the scheme is robust against common signal processing attacks, meanwhile security of the algorithm is guaranteed by using secret keys. Therefore, the scheme proposed in this paper is suitable for certain application.