本文结合图像传感器的实际像元感光区形状和像元填充率，提出了一种改进的质心算法。该方法根据不同像元感光区形状和像元填充率下感光区中心坐标不同的特点，通过修改传统质心算法中像元坐标的取值来提高质心算法的定位精度。在分析星点的灰度分布特点的基础上，明确了如何仿真产生一个星点光斑，并通过仿真实验验证了改进质心算法的有效性。实验结果表明：在理想情况和噪声存在情况下，改进质心算法的定位精度优于双线性插值质心算法和传统质心算法。

An improved centroid algorithm was put forward considering the actual pixel photosensitive area shape and pixel fill factor of image sensor, which is based on the characteristic of different pixel photosensitive area shape and pixel fill factor with different coordinate values of the photosensitive area center. The locating accuracy was improved by modifying the values of pixel coordinates in traditional centroid algorithm. How to simulate a star point was described by analyzing gray scale distribution characteristic. The effectiveness of the improved centroid algorithm was verified by simulation. The simulation results show that the locating accuracy of the improved centroid algorithm is superior to the bilinear interpolation centroid algorithm and the traditional centroid algorithm both in ideal and noise situations.