Digital Audio Watermarking Theory And Method

In recent years, MP3 music has become extremely popularized owing to its advanced coding techniques, however, with the development of digital networks and multimedia processing technology, MP3 music is much easier to be edited, duplicated and distributed, leading magnitude economic losses to the owner of the music. Therefore, the copyright protection of the MP3 music becomes more and more important. Traditional encryption techniques, which can only provide limited extent of protections, are insufficient in security and in communication. Digital watermarking technology, considered as a potential solution, has brought the cause to the attention of the world and is becoming an international academic focus.This dissertation focuses on research on watermarking algorithms of digital audio. The main content includes:(1)A new adaptive digital audio watermarking based on DWT and DCT is proposed. It makes full use of the multi-resolution of DWT and the energy compression of DCT. The watermark is embedded into the low frequency components by adaptive quantization according to the local audio correlation.(2)According to the characteristic of MP3, a novel audio watermarking algorithm is proposed. As compared with other systems with the same quantization step, the proposed method is imperceptible through adopting the adaptive ones. By using the adaptive piecewise strategy, this algorithm is still effective though the length of the file has been changed after MP3 compression.(3)A robust digital audio watermarking algorithm is presented, which can resist desynchronization attack effectively. We embed synchronization code by modifying the mean value of several samples. Experimental results show that the proposed watermarking scheme is robust against synchronization attack and general signal processing.