The Research On Audio Digital Watermarking Algorithm

With the development and applications of computer communications and signal processing technologies, multimedia products, such as digital image, audio and video, have been popularized and applied increasingly and widely. But the digital products can easily be copied, edit and transmit, so how to take measures to enable copyright protection and information safety in the network, has became an important problem that shoule be solved in digital communication field immediately. Digital watermarking technique is the most effective method to solve copyright protection. With the products of digital audio products, the copyright protection of audio products becomes more and more important. Recently, audio digital watermarking technique has been recognized and researched, the frictions such as copy control, using tracing, can be realized by embedding the watermarking in the audio signal.The paper has been researched mainly on the algorithms of audio digital watermarking. It anlalyzes the theory of audio digital watermarking and the characters of audio digital watermarking system, from the point of improve the watermarking imperceptibility and robust, based on the analysis, comparison and test of existing digital audio watermarking algorithms, some digital audio watermarking algorithms are proposed and improved. The main research work and contributions of the dissertation are as follows:(1) In the discrete cosine transform domain, put forward an audio watermarking algorithm based on mean_quantization. The algorithm increase the watermarking security by disordering the watermarking. Applying the BCH coding technique to the watermark can increase the correctness of watermark extraction. Enbedding the watermark on the low-frequency and middle-frequency of DCT using mean_quantization theory improves the watermark's imperceptility and robust. The watermark can be extracted without the original audio.(2) Applying Spectrm-spread communication theory, an improved DCT audio watermarking algorithm has been put forward. First, the audio signal has been divided and DCT, the watermark image will be embedded into the low-frequency of DCT based on mean_quantization theory. Experimental results show that the performance of this scheme is good infragility. The watermark can be extracted without the original audio.(3) A new blind digital audio watermarking algorithm is proposed for audio data security. First, the audio signal has been divided and SVD, the watermark image will be embedded into the low-frequency of SVD based on mean_quantization theory. The watermark image has been processed by Arnold disorder transform. Experimental results demonstrate that the method is robust and imperceptible. The watermark can be extracted without the original audio.