A Robust Grayscale Watermarking Scheme Using Angle Quantization

Abstract

Digital life has been an important being of human life with the development of computer science, and the multimedia tort has become serious. Digital watermarking techniques support an efficient copyright protection, as well as the integrity and the ownership of multimedia can be protected by watermarking techniques. In this paper, the discrete wavelet transformation (DWT) is used, and the middle-frequency DWT coefficients are used to generate vectors. The purpose of embedding watermark is achieved by quantizing and adjusting the angle of the vector. Experimental results show that our proposed scheme has a better performance for JPEG lossy compression, and is robust against attacks such as rotation, rescaling, cropping, noise addition, blur, sharpness and brightness adjustment.