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The Research Of Audio Digital Watermark Algorithm

Posted on:2005-03-11Degree:MasterType:Thesis
Country:ChinaCandidate:J B HuangFull Text:PDF
GTID:2168360122490316Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
The audio digital watermark technology is one of the research focuses in recent years through embedding secret information into digital audio signal on purpose of copyright protection, information security and so on. It can be proved through detecting the watermark when owner's rights and interests are infringed. With a large amount of facture and issuance of the digital video product and music products, the copyright protection of the audio data seems to be more and more important too. Through embedding watermark information into audio carrier, the function of copy restriction, use track and the pirate confirmation can be realized. In recent years, the research about the audio digital watermark technology is developed quickly. Especially the technology of audio digital watermark in the transform domain, make research have practicability because it can embed information to sensitive area of the carrier.In this paper the visually recognizable binary image is selected as watermark information, which is embedded in the transform domain through transforming the original audio signal (discrete cosine transform and discrete wavelet transform).In chapter 3, a kind of audio digital watermark algorithm in DCT domain on the basis of spreading spectrum technology is used and quantification scheme is provided. The algorithm can detect the watermark without the original digital audio signal, so it is a kind of blind watermark algorithm. Equally, spreading spectrum technology can improve the performance of watermark technology greatly, but it will increase the capacity of channel and the calculation of the algorithm as cost. In order to test the robustness and imperceptivity of the algorithm, simulate experiments are carried out. The experimental results indicate that it is robust to the attack such as mp3 loss compression, low pass filter, resample and so on.In chapter 4, an adaptive audio digital watermark algorithm presents. With the algorithm based on m-sequence modulation, firstly, the visually recognizablebinary watermark image should be converted into the one-dimensional sequence in the algorithm. The sequence is permuted pseudo-randomly and is modulated by m-sequence. Then the digital audio signal is set into segments and DWT is performed. Finally the modulated signal is embedded in the coefficients with relatively large absolute value on middle frequency range detail signal adaptively. The original digital audio signal is necessary when detecting the watermark. Equally, spreading spectrum technology can improve the performance of watermark technology greatly, but it will increase the capacity of channel and the calculation of the algorithm as cost. In order to test the robustness and imperceptibility of the algorithm, simulate experiments are carried out. The experimental results show that the watermark is imperceptible and the algorithm is robust to digital audio signal when attacked by low pass filter, re-quantified and so on.
Keywords/Search Tags:audio digital watermark, spread spectrum technology, discrete cosine transform (DCT), discrete wavelet transform (DWT)
PDF Full Text Request
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