The Research On Digital Audio Watermarking Technology Based On Spread Spectrum

With the rapid development of the Internet and multimedia technologies, people can use the Internet technology to disseminate and replicate pirated audio products without getting copyright owner’s aggrement. As a result, the digital watermarking technology becomes one kind of the copyright protection means because of the copyright owners’ interests suffering great damage. But with the shortcomings of the difficult watermark is to implementation process embedded in the audio signal and poor anti-attack capability,making audio watermarking algorithm research and improving its anti-interference capability have become an urgent problem to be solved.This research use spread spectrum technology to achieve watermarking algorithm in the transform domain. Then, two kinds of watermarking algorithms are analyzed based on the embedding position of the watermark. The research contents are as follows:The first way is to scramble the original watermark information and then make the spread spectrum. The original audio signal is decomposed to low frequency components by discrete wavelet transform, and then the low frequency component is decomposed by the singular value of the diagonal matrix. In order to fulfill the embedment of watermark information, this paper modifies the first singular value of the diagonal matrix using the watermark information. Through the simulation experiment and by using PSNR and other standards, it can be found that the algorithm has good robustness;The second way is to scramble the original watermark information and then make the spread spectrum. The original audio signal is decomposed to high frequency components by discrete wavelet transform, and then the high frequency component is decomposed by the singular value of the diagonal matrix. In order to fulfill the embedment of watermark information, this paper first determines the size of embeddment based on the masking effct of human eras, and then modifies the singular value of the diagonal matrix by using the watermark information. Through the simulation experiment, this research improves the security of the watermark algorithm and the algorithm is sensitive to common attacks.The result of MATLAB simulation experiment shows that the watermark algorithm based on spread spectrum improves the security of watermark information. The watermark algorithm embedded into the low frequency component has good robustness, which can protect the copyright. The watermark embedded into the high frequency component ishighly affected in the environment of low pass filter and MP3 lossy compression attack experiment which proves the algorithm’s robustness is not high and is sensitive to attack.So the watermark embedded into the high frequency component can authorize the watermark’s content completeness.