基于图像处理的声相云图评价方法研究

Research on Evaluation Method of Acoustic Phase Image Based on Image Processing

基于图像处理,提出了声相云图评价方法,用于评价声相仪的声源定位误差。分析了声相仪的成像原理,提出将方位角误差和俯仰角误差作为声相云图声源定位误差的评价指标。利用差影法提取声相云图的声源定位成像区域,并经过灰度二值化、腐蚀膨胀和加权平均之后,计算出成像区域中心的像素坐标。在声相仪不同抓拍距离平面内,通过图像标定得到成像区域中心在实际物理空间上的位置坐标,将其与所定位的声源实际位置坐标相比较,计算得到方位角误差和俯仰角误差。实验结果表明,该方法所得方位角和俯仰角与声源实际位置坐标计算所得到的真实值相比,两者差异较小,能够客观地对声相仪的声源定位误差进行评价,且操作简单。

Based on image processing,an acoustic phase image evaluation method is proposed to evaluate the sound source positioning error of the sound imaging instrument. Analyzing the imaging principle of sound imaging instrument,and the azimuth error and the pitch angle error are proposed as the evaluation indexes of the acoustic phase image’s sound source positioning error. The difference image method is used to extract the sound source localization imaging region of the acoustic phase image. After going through grayscale,binary,corrosion,expansion and the weighted average,the pixel coordinates of the imaging region’center are calculated. In the different capture distance planes of the sound imaging instrument,the position coordinates of the imaging region ’scenteron the actual physical space are obtained by image calibration. Then comparing with the actual position coordinates of the positioned sound source,the azimuth error and the pitch angle error are calculated. The experimental results show that comparing the azimuth and pitch angle obtained by the proposed method with the actual value obtained by calculating the actual position coordinates of the sound source,the difference is small,which means that the sound source positioning error can be objectively evaluated and the method is easy to be operated.