Audio Watermarking Technique Based On SVD_DWT

For the widespread application of computer and internet, it is very convenient for us to obtain the information and communicate with each other. At the same time, it is much more important to protect the copyright of digital data. As an effectual means for protecting the copyright, the digital watermarking had been researched widely. In recent years, the research of digital watermarking was mostly based on the static images imbedded. Due to the big difference of vision and audition of human being, it is difficult to imbed digital watermarking into the audio signal.In this paper, two kinds of robustness audio digital watermarking method were proposed, with the two-dimension binary image as watermark information, the audio data as carrier data, on the basis of Singular Value Decomposition and Discrete Wavelet Transform.(1) The audio signal was decomposed by using appropriate wavelet basis. Low frequency coefficients were selected and SVD of the divided signals was made. At the same time, the watermark was constructed by Singular Value Decomposition , and obtained a singular value vector. Then with the aid of a watermark image singular value diagonal vector, watermark embedded process was realized. Three kind of audio samples were carried on the robust test, such as pop music, classical music and speech. It was be maked the quantitative evaluation with the normalized correlation coefficient and the signal-to-noise ratio. Experimental results showed that method in this chapter was robust to many attacks, such as resampling, low pass filtering, noise addition ,cut and so on. This algorithm shortcoming was that when the watermark was extracted, it needed the primitive watermark information. So it would be restricted in the practical application.(2) The previous kind was not improved which the blind watermark algorithm had be carried on. First, before watermark embedded, the watermark image was carried on Arnold transformation in order to realize covert effect. Afterward, the original audio signal was decomposed using appropriate wavelet basis. Low frequency coefficients were selected to divide into section and SVD of the divided signals was made. The singular values were chosen and embedded into the watermark image by quantization method. The using of the scrambling encryption, provided the security of the watermark. The using of the partition singular value decomposition, enhanced the watermark inserting speed and saved many running time. Normalized correlation coefficient and signal-to-noise ratio were compared with based on SVD watermark embedded method, The results of experimentation showed the watermark hideaway effect was slightly bad except the denoise attack, others had the good robustness. In particular, the watermark could be extracted without the original digital audio signal, it would be in favor of the actual application.In conclusion, it is mostly purpose that the singular value stability in the Singular Value Decomposition can control noise to audio data influence. The using of the Wavelet transform improves the imperceptible of the watermark.