8 October 2015 Optimum threshold selection method of centroid computation for Gaussian spot
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Proceedings Volume 9675, AOPC 2015: Image Processing and Analysis; 967517 (2015) https://doi.org/10.1117/12.2199247
Event: Applied Optics and Photonics China (AOPC2015), 2015, Beijing, China
Centroid computation of Gaussian spot is often conducted to get the exact position of a target or to measure wave-front slopes in the fields of target tracking and wave-front sensing. Center of Gravity (CoG) is the most traditional method of centroid computation, known as its low algorithmic complexity. However both electronic noise from the detector and photonic noise from the environment reduces its accuracy. In order to improve the accuracy, thresholding is unavoidable before centroid computation, and optimum threshold need to be selected. In this paper, the model of Gaussian spot is established to analyze the performance of optimum threshold under different Signal-to-Noise Ratio (SNR) conditions. Besides, two optimum threshold selection methods are introduced: TmCoG (using m % of the maximum intensity of spot as threshold), and TkCoG ( usingμn +κσ n as the threshold), μn and σn are the mean value and deviation of back noise. Firstly, their impact on the detection error under various SNR conditions is simulated respectively to find the way to decide the value of k or m. Then, a comparison between them is made. According to the simulation result, TmCoG is superior over TkCoG for the accuracy of selected threshold, and detection error is also lower.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Xuxu Li, Xuxu Li, Xinyang Li, Xinyang Li, Caixia Wang, Caixia Wang, } "Optimum threshold selection method of centroid computation for Gaussian spot", Proc. SPIE 9675, AOPC 2015: Image Processing and Analysis, 967517 (8 October 2015); doi: 10.1117/12.2199247; https://doi.org/10.1117/12.2199247


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