The Research For Double Compression And Resampling Detection Of Digital Audio

The authentication and integrity of digital audio are attracting more and more attention from researchers. Along with the wide use of audio processing softwares, it becomes more easily for people to tamper the audio content which makes audio forensics much harder. Many methods have been proposed to detection tampering process such as re-sampling, double-compression, copy-paste and so on, then we can know the authentication of the audio.This paper mainly focuses on the research of the authentication of digital audio. Two new detection methods are proposed respectively according to the double mp3 compression tampering and the audio interpolation tampering. The main structure of the thesis is as follows:(1)The paper gives a comprehensive introduction to the history detection of digital audio including the researching background and status. Then we generalize the characteristic of the digital audio, the forgery tools and the methods to detection audio forgeries.(2) Through analyzing the effect of MP3 compression to quantized MDCT coefficients, The approach of detecting double mp3 compression based on quantized MDCT coefficients is proposed in this paper. Based on the fluctuation coming from the double compressed MP3, which don't exit in single compression, statistical features reflecting the period of the detected audio can be extracted. Thus we can detection the authentication of the mp3.Experiments show that the detection accuracy of the proposed approach compered with paper [17].(3)According to the limitation of the existing methods, such as high complexity and limition, the method for detecting audio re-sampling is proposed based on the characteristic of the interpolated audio signal. Through extracting the variance of the second derivative of an interpolated signal, we can get the peak features. Then we can detection the authentication of the signal and calculate the interpolation factor. Experiments show that the method is effective both for local and global interpolation.At the end of the thesis, we give a summarization of the main contents and the possible future research areas of the audio forensic.