Research On Audio Information Hiding Method Based On Spread Spectrum And Echo

In recent years,with the vigorous development of computer network technology,more and more traditional media products have been transformed into digital ones.It is becoming easier and easier to store,copy and disseminate digital audio works,which also leads to a series of adverse consequences,such as random copying,tampering with some audio works,and copyright disputes occur from time to time.Digital audio watermarking technology can realize copyright protection of digital products.This technology can achieve the purpose of copyright protection by embedding secret information in audio files.At present,there are many watermarking algorithms for audio,but these algorithms have some defects,among which the robustness and transparency of watermarking algorithm is a difficult problem to balance.Echo hiding technology and spread spectrum technology are both important branches of digital watermarking technology.This dissertation,an audio watermarking algorithm based on spread spectrum and echo is designed by combining the echo hiding of PN(Pseudo-Noise)sequence with spread spectrum of Complete Complementary Code to further improve the robustness and transparency of the watermarking algorithm.The main contents of this dissertation are as follows:Firstly,an echo hiding method based on PN sequence was proposed.This method expands the introduction of echo uniformly in time domain.At the same time,the attenuation coefficient of embedded watermarking was adaptively adjusted by the short-term energy value of each audio band to complete the processing of carrier audio.The polarity of forward and backward echo cores is changed by PN sequence,and the echo cores are encrypted so that the echo cores can be encrypted with very small echo amplitude.This method can better embody the security and invisibility of the watermarking while maintaining high detection rate.Secondly,on the basis of analyzing the invisibility,robustness and security of various digital audio watermarking algorithms,a watermarking algorithm based on spread spectrum and echo is proposed,which combines echo hiding and spread spectrum.The watermarking sequence is spread spectrum by using Complete Complementary Code technology.Because the Complete Complementary Code has complete randomness,the watermarking sequence is spread spectrum modulated by complete randomness.Combined with the short-time energy echo hiding method of PN sequence,the watermarking information after spread spectrum modulation is superimposed on the time-domain waveform of audio signal,and the embedding position is selected adaptively to embedding the watermarking information.Complete complementary codes have better anti-noise performance and can improve the robustness of watermarking.The experimental results show that the proposed algorithm can satisfy the good hiding effect of the watermarking.On the basis of ensuring the transparency of the watermarking,the embedding strength increases gradually.The detection rate of the watermarking information is over 98%.It has strong robustness against noise,filtering and resampling attacks.The detection rate of the watermarking information is over 90%,and the extraction effect of the watermarking is good.By changing the distance and angle between the sender and the receiver,the experimental results have higher signal-to-noise ratio and lower bit error rate.The watermarking algorithm designed can accurately detect the watermarking.This algorithm has great advantages in protecting the copyright of audio works.