The Research And Implementation Of Digital Audio Watermarking Based On The Transform Domain

The development of Internet and multimedia technology making the digital media began to gradually replace the traditional media to become the main form of the media. People can easily get lots of digital products from the Internet, but it also brought a range of copyright issues. The emergence of the digital watermarking technology provides a new way for copyright protection, and gradually become a hot research topic.The main study of this paper is about digital audio watermarking technology. Audio Digital Watermarking is a branch of Digital watermarking. The main purpose of the studies is protect the music copyright. By hiding the copyright information into the music products to make people can easily confirm the copyright. The studies of the audio watermarking technology in this paper are based on the transform domain techniques.This paper introduces the background of digital watermarking, application and research status at first. And then introduces the definition of digital audio watermarking, the basic model and the principles of audio digital watermark evaluation criteria. And also describes the basic knowledge of signal processing, and the human auditory characteristics, the audio format characteristics. After the discussion of watermarking technology currently available, by using the discrete cosine transform (DCT) and discrete wavelet transform (DWT), presented two improved audio watermarking algorithm based on the transform domain techniques.1.Using discrete cosine transform for watermark embedding, the goal of the algorithm is to make the embedded watermark can be used as much as possible without affecting the audio quality, and make the algorithm satisfies certain robustness and to simplify the algorithm to reduce the complexity of the algorithm. To solve the problem of Digital audio watermarking in the DCT domain don't have enough transparency, this paper analysis the effect of audio quality by changing the DCT coefficients. According to the conclusions of the discussion, this algorithm is using the hearing sensitivity difference of energy changing and adjusting the strength of embedding watermark to achieve the balance of transparency and robustness.2.Using the wavelet transform and discrete cosine transform to embed the digital watermark. To solve the contradiction between the robustness and transparency in DWT watermarking. This paper analysis the relationship between the DWT and the human auditory system. After those discussions this paper presented an algorithm to use DWT to simulate the critical band division, and to embed watermark in particular band. And use some conclusions of ChapterⅢ, to use DCT to strengthen the robustness of the watermark.The advantages of these two algorithms are:1. Low complexity, easy implementation.2.These algorithms both use the human auditory characteristics, good transparency.3. Watermark image use Arnold transform, good security.4. After audio attacking it can still extracted the digital watermark, strong anti-attack;5. The extraction of Watermark does not need the participation of the original audio, it is a Blind watermarking algorithm, wide application.Those two algorithms were implemented, and analysis security, transparency and robustness by experiment. The results show that both of algorithms have good security, transparency and robustness, they are effective audio digital watermarking algorithms-these can be used in the copyright protection.