基于改进Zernike矩的远场激光高精度中心测量

High precision center measurement of far-field laser based on improved Zernike moments

针对远场激光光斑分布不均匀、形状不规则的特性,提出一种基于改进的Zernike矩的远场激光高精度中心测量方法。在传统Zernike矩亚像素边缘检测基础上,使用新型的logistic边缘检测模型和阶跃阈值自适应提取方法,在减少人工对阶跃阈值误判的同时,提高对实际边缘的识别精度,最后使用最小二乘法椭圆拟合得到高精度激光光斑中心。该方法在远场激光中心检测中,单帧误差在0.5 pixel左右,连续多帧中心偏差波动在1 pixel以内,拥有较高的精度和可靠的稳定性。

Aiming at the features of nonuniform distribution and irregular shape for far-field laser spots,a measurement method based on improved Zernike moments was proposed to identify the far-field laser spot center.Firstly,the image was denoised by bilateral filtering.Then,based on traditional Zernike moment subpixel edge detection,a new logistic edge detection model and step threshold adaptive extraction method were used to improve the accuracy of actual edge recognition,as well as reduce the manual misjudgment of step threshold.Finally,the least squares ellipse fitting was used to obtain the high-precision laser spot center.This method has a single frame error of about 0.5 pixel in far-field laser center detection,and a continuous multi-frame center deviation fluctuation of less than 1 pixel,which has high accuracy and reliable stability.