提出了一种基于功率倒谱统计特征的音频回声隐写分析方法.首先对音频信号进行分段和加窗,然后对加窗后的音频信号段求平均功率倒谱,利用回声隐藏信号的平均功率倒谱能够在回声延迟处产生峰值这一特点,对平均功率倒谱求差分方差和平坦度作为统计特征,采用支持向量机进行分类.该隐写分析方法不仅能够对最基本的单回声核进行检测,还适用于改进的回声核.实验证明,本方法的效果令人满意,在衰减系数较低的情况下也能达到较高的分类准确率,且无论嵌入段长如何,都能较为准确地检测.
An audio steganalysis method for echo hiding based on statistical features of power cepstrums was proposed.In this scheme,audio signals were first divided into little segments and a hanning window was applied to each segment,then average power cepstrums of the windowed audio segments were calculated,and based on the feature that the average power cepstrums of echo hiding signals can generate peaks at echo delays,variances of differences and flatness of the average power cepstrums were calculated as statistical features,and,finally,support vector machine(SVM)was implemented as a classifier.This steganalysis method can not only detect the basic single echo kernel,but also be applied to the improved echo kernels.Experimental results show that the performance of the proposed method is satisfactory,achieving high classification accuracy even with low attenuation coefficients and regardless of the length of the embedded segments of audio signals.