基于互相关和改进高斯拟合的光斑中心提取方法

针对差分激光三角法海面溢油油膜厚度测量系统 中光斑图像中心提取的问题,在分析用 于系统标定的陶瓷量块和所测量的石油表面光斑图像特征的基础上,采用互相关与改进型高 斯拟合的算法对光斑中心进行提取。算法首先采用标准高斯图像模板与光斑图像进行互相 关,得到了保留图像特征且光顺的光斑图像；然后,利用上下边沿信息进行高斯计算的改进 型高斯拟合方法进行光斑图像拟合,由拟合得到的高斯图像参数计算出光斑中心坐标。通过 本算法与目前已有的平方加权质心法、高斯拟合法、改进型高斯拟合法和互相关高斯拟合法 对图像光斑中心提取结果的比较与分析,得出互相关和改进高斯拟合相结合的方法在光斑提 取重复性精度,以及使用本算法对陶瓷量块厚度测量精度均好于其它方法,并对石油表 面图像进行了中心提取实验。结果表明,本文算法适合于差分激光三角法海面溢油油膜厚度 测量系统的光斑提取。

Spot center extraction based on cross correlation and improved Gaussian fittin g

According to extracting the center coordinate of spot in an oil film thicknes s measurement system with differential laser triangulation,based on the analysi s on spot image features of ceramic gauge block and oil film,a method of spot po sitioning is presented with cross correlation and improved Gaussian fitting.The s mooth and feature reserved spot image is obtained through the correlation operat ion of the spot image and a Gaussian mask image.The center coordinate of the sp ot image is obtained by improved Gaussian fitting with the ascending edge and de scending edge data of the correlation results extracted for fitting.To verify th e performance of the method,experimental measurement is carried out with differ ent spot center extraction methods.Compared with square weighted centroid met h od,Gaussian fitting method,improved Gaussian fitting method and cross correlat ion Gaussian fitting method,the precision of the presented mothod is higher.The experiment of oil film spot center extraction is carried out.The results show th at the algorithm presented is feasible for oil film thickness measurement system with differential laser triangulation.