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

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.