Audio Digital Watermark Algorithm

Recently, with computer and internet is popular, multimedia products such as image, vide, audio, such as VCD MP3, have been popularized and applied increasingly and widely, so much audio and vide archives has been stored as digital files, the efficiency and correction of communication have been improved clearly. Now we can find many electronic library and archives in the network. But the side effect with it is that, some persons and organized can easily copy, edit and transmit the content without the permission of the copyright ownership. So how to take measures to enable copyright protection and information safety in the network, has became a problem that should be solved immediately. Digital watermarking technique is the most effective method to solve copyright ownership. But the current watermark information algorithms applied widely are related with image and video. The watermark algorithms of audio and speech is few especially, we must find more and more effective watermarking algorithms for audio and speech data. This dissertation selects two-dimension binary image as watermark information, and selects audio as embedding object, and embed the watermark information, and selects audio as embedding object, and embed watermark in the coefficient of the DFT domain, the DCT domain, the DWT domain. The main research work and contributions of the dissertation are as follows:(1) The dissertation reviews the relative issues and current research status of audio digital watermark.(2) In the discrete Fourier domain, the watermark information is embedded by quantifying the amplitude of the DFT domain coefficient;in the same time, the quantification procession and the provision that must be met in the modifying of amplitude is given. The watermark can be extracted without the original audio.(3) In the discrete cosine domain, the watermark is embedded by quantifying the coefficient of the DCT domain, Spectrum-spread is applied. The watermark can be extracted without the original audio.