模拟尾流气泡幕的灰度图像分析

为了对舰船尾流产生的大量气泡进行实时探测,对气泡的密度分布进行了分类判别,利用灰度图像直方图统计矩法,分析了随着压强增大,灰度直方图的峰值由较暗向较亮方向移动.应用图像处理技术对不同压强下模拟尾流气泡幕的统计特性参数(均值、三阶矩、标准偏差、归一化、一致性、熵)进行分析,研究结果表明:随着压强的增大气泡幕图像的均值递增说明平均灰度级在递增;三阶矩呈递减状态反映了图像灰度直方图的"歪斜程度";在其他4个参数的曲线中0.025 MPa所对应的值说明了所采集的气泡幕图像的纹理特征比0.02 MPa,0.03 MPa,0.035 MPa压强下的要粗糙;所提取的六个特征参数准确的表征了不同压强下气泡幕的特征.

Analysis of the Gray Images of Simulated Wake Bubble Film

In order to detect the large number of bubbles created by ship wake in real-time,the density distribution of bubbles is classified.It is shown by the gray histogram statistical moment method that the gray histogram peak shifted from dark to light with the rise of pressure.Statistical parameters（mean value,standard deviation,the third moment,uniformity,normalized coefficient,entropy） of simulated wake bubble films（WBF） under different pressures were analyzed by using image processing technology.The results show that the mean value increases with the rise of presure,suggesting that the average gray level is ascending,while the decreasing third moment reflectes the symmetry of WBF gray image.The curves of the other four parameters illustrate that the texture features of WBF image under the pressure of 0.025 MPa were rougher than those under the pressures of 0.020 MPa,0.030 MPa and 0.035 MPa.The six parameters represente accurately the characteristics of WBF under different pressures.