Centroid detection of laser spots in large plane optical components topography measurement system

One of the core issues of the large plane optical components topography measurement system is calculating the centroid coordinates of laser spots quickly and accurately, which determines the accuracy and repeatability of the measurement. According to visual perception, a 1D detection window with radius as r was defined, to find the local maximum energy in the field with a convolution template depending to center distance. Then traditional centroid method was used to calculate the subpixel centroid. Finally, 3 rule of error processing was applied. The experimental results show that the detection accuracy of proposed algorithm is 0.1 pixel, and the index was improved about 1 time than existing threshold weighted centroid method. The similarity and PV of topography is closer to interferometer than threshold weighted measurment. It has been successfully applied in actual projects.