基于图像处理的回声定位信号检测方法

鲸豚类海洋哺乳动物发出的回声定位信号是一种频率较高的短时脉冲信号,研究回声定位信号检测方法有助于快速、准确地检测海洋哺乳动物发声,进而更好地保护海洋哺乳动物.本文提出了一种基于图像处理的鲸豚类动物回声定位信号检测方法.该方法首先对收集到的数据进行分帧,计算每帧信号的时频图;使用Frangi滤波器对时频图进行滤波,以降低...

Detection Method for Echolocation Clicks Based on Image Processing

Odontocetes echolocation click is a kind of short-time signal with high frequency.Research on the detection method of echolocation signal is helpful for the rapid and accurate detection of marine mammal vocalization,so as to better protection of marine mammals.A method based on image processing is proposed to detect odontocetes echolocation clicks.The collected data are divided into fixed-length frames and the time-frequency diagram of each frame is calculated.The spectrogram images of click signals are filtered to remove noise and enhance the line-shape signals.Considering that the echolocation signals are like lines in time-frequency domain,line detection is subsequently used to obtain the precise position of the signal,and then to acquire the feature of signals.Finally,a Random Forest Classifier was trained to obtain a detector to distinguish between click and non-click clips.Experiments were carried out using acoustic data of Mesoplodon densirostris,Globicephalamelas,Eubalaena japonica and Orcaella brevirostris.The performance of the proposed method was evaluated using real audio recordings.The experimental results indicate that comparing with the traditional energy detector method,the proposed algorithm shows higher recall and precise under low signal-to-noise ratio(SNR).The proposed method can provide technical support for marine bioacoustics study.