Study Of Watermarking For Images Based On Wavelet Transform And B-Spline

With the rapid development of computer network and multimedia technology, especially the popularization of the Internet, information security has been a key and attractive problem. As an effective method for protecting the copyright of multimedia data in digital world (watermarking), information hiding has been widely studied and applied in the past few years.This thesis discusses information hiding, which emphasizes on digital watermarking for images. Firstly, it introduces general concepts and fundamental principles of information hiding such as the definition, characteristics, classification and application. Secondly, it addresses the processing model, general framework, the typical methods, the attack analysis and the main application of digital watermarking. Then, a novel digital watermarking scheme based on wavelet transform and B-spline is proposed in this thesis. The embedded watermark is invisible to human eyes and adapted to the original image by exploiting human visual system masking characteristics. The experimental results show that the proposed algorithm is effective and robust to common image processing operations and some geometric distortions. Supported by the experiments, the performance analysis of the proposed scheme is also made in this paper. Finally, a conclusion can be made that the proposed technique is practical.