摘要
分析了扩展目标在Shack-Hartmann传感器中的成像特点。针对成像特点,提出了一种提取子光斑位置的质心计算方法。该方法应用多阈值分割和多结构元形态学去噪预处理后再进行质心计算。在信噪比低、扩展度大的情况下,能够有效地抑制噪声,减小噪声对质心计算精度的影响。在不同信噪比和扩展度下,相对于一般质心方法,该方法能够显著地提高探测精度。当信噪比为0.5,扩展度达13时,该方法的平均绝对误差不到1个像素。
The characteristics of a sub-aperture spot image formed by extended object in Shack-Hartmann wavefront sensor were analysed. Based on the image characteristics, a new centroid calculation method for extended object with low Signal to Noise Ratio （SNR） is presented. By using multi-threshold segmentation and denoising with mathematical morphology, the method is very accurate for calculating extended object with low SNR. Furthermore, simulation is performed and the result is presented. The mean absolute error is less than 1 pixel when the extension degree equals 13 and SNR is 0.5.
出处
《光电工程》
EI
CAS
CSCD
北大核心
2005年第8期9-12,共4页
Opto-Electronic Engineering
关键词
质心计算
形态学
低信噪比
扩展目标
Centroid calculation
Mathematical morphology
Low SNR
Extended objects
