基于ENF邻域相关系数的音频篡改盲检测

Blind Detection of Audio Forgery Based on ENF Neighborhood Correlation Coefficient

为了提高现有的基于电网频率(electric network frequency,ENF)信号的盲篡改检测方法在低信噪比时的检测准确率,提出一种利用ENF信号邻域相关系数的音频篡改盲检测方法.首先将待测音频中提取的ENF信号划分子块,并计算相邻区域子块的相关系数;然后对相关系数序列进行自适应快速横向滤波(fast transversal filter,FTF),根据误差能量的变化检测音频篡改.为了减小干扰的影响以提高篡改检测准确率和篡改定位精度,从正、反两个方向对音频进行上述处理,再结合两个方向的误差能量进行篡改检测.与现有的两种代表性方法相比,所提出的方法不但能精确定位篡改,而且能有效提高音频篡改的检测准确率,尤其是在ENF波动较大和信噪比较低的情况下更有优势.

In order to improve the accuracy of the existing blind tamper detection meth- ods based on electric network frequency （ENF） in the case of low SNR, we propose a novel blind detection approach based on the ENF cross-correlation coefficients in neigh- borhood. First, the ENF signal extracted from the query audio is divided into blocks, and the cross-correlation coefficients of the adjacent blocks are calculated. Then the adaptive fast transversal filter （FTF） is performed to the coefficient sequence. According to the variation of the filtering error energy, we can detect audio forgery. In order to reduce the interference and improve the accuracy of forgery detection and localization, the audio is processed in both forward and backward directions. Then the two directions＇ error energies are combined to detect forgery. Compared with two existing representative methods, the proposed method performs excellent accuracy both in forgery location and forgery detec- tion. Especially under the circumstances of larger ENF fluctuation and lower SNR, the method shows more advantages.