Research On Robust Digital Audio Watermarking

With the rapid development of multimedia technology and communication technology, the transmission of multimedia works such as audio, images and video transmission on the network is very convenient, but at the same time, music works represented by MP3 are wantonly spread and reproduced through the internet. It brings about serious harm to the owner and the publisher of the works. So it is necessary to provide copyright protection for digital audio works. Robust digital audio watermarking research for this protection provides an effective solution. Digital audio watermarking technology is an effective way to embed some marks in the digital audio signals that are not easily awared of by the Human Auditory System. By the detection of these marks, the owner or publisher of the audio works can be identified, and it can also be confirmed whether the works is complete. Because Human Auditory System is more sensitive to Human Visual System and the research of the audio watermarking is mostly copied from image watermarking technology, it is a big challenge of the research to choose digital audio watermarking as the research topic of the thesis.The thesis is mainly on robust digital audio watermarking. The following works have been done:1. Because of the close relationship between the digital audio watermarking and the human auditory system, this chapter introduces the characteristics of human auditory system first, including absolute threshold of audibility and masking effect of human ear..Then it summarizes the digital audio watermarking technologies including the watermark generation, watermark embedding, watermark extraction and detection. Analysis on some common audio watermarking algorithms including time-domain, transform domain and compressed domain algorithms is conducted. Finally, an overview of common assault and evaluation criteria of digital audio watermarking system is presented.2. Because the frequency points of DFT-based digital audio watermarking algorithm are relatively fixed and open, it may cause potential safety problems. In order to overcome them, this chapter introduces NDFT-based algorithms. First it introduces the basic principles of NDFT, which is the foundation of digital audio watermarking algorithms based on the nonuniform discrete Fourier transform. Two digital audio watermarking algorithms based on NDFT—the algorithm of comparison for two adjacent segments and three adjacent segments are proposed. The former embeds the marking by adjusting the value of two adjacent segments, while the latter embeds the marking by adjusting the value of three adjacent segments. The simulation shows that the two algorithms in this chapter have high robustness to normal attacks.3. For the security of DRM system, this chapter presents a DRM system by combining digital audio watermarking and encryption technology. First it introduces the development of DRM, and then it details the structural elements of DRM systems-password and watermarking. A design of a DRM technological system of security is given. Finally, simulation of the audio watermarking technology in DRM system is conducted and the simulation results show that the quantized audio watermarking algorithm can completely adapt to the non-sensible and robust requirements in DRM.