基于均值漂移实现非发射线天体光谱的谱线自动提取

非发射线天体的光谱是天体光谱谱线提取中最难处理的一种。针对非发射线天体，给出了一种基于均值漂移的谱线自动提取方法。首先，利用均值漂移总是指向局部密度最大点也即密度的模式点这一性质，提取出较为满意的伪连续谱;其次，均值漂移滤波同时工作在空间域和幅度域上，是一种非线性的边缘保持滤波方法，在去除噪声的同时，能够较好地保持特征谱线的信息，文章在连续谱归一化后，采用均值漂移去噪得到谱线光谱;最后，对谱线光谱设置局部阈值提取出特征谱线。通过对恒星、正常星系等的实验表明：该方法是有效的, 这将对后续的参数测量和基于谱线的光谱分类非常有利。

Mean Shift Based Auto- Extraction of Spectral Lines for Non-Emission-Line Objects

The mean shift algorithm is used. At first, the property that mean shift vectors always point toward local maxima of the density is used to get the pseudo continuum; secondly, mean shift filtering is a good edge preserving smoothing, which can adaptively reduce the amount of smoothing near feature spectral lines, so the authors use mean shift filtering in noise reduction after the normalization of continuum spectra; finally, the authors extract feature spectral lines by setting local thresholds. The experiments on both stars and normal galaxies show that our method can extract spectral lines accurately, which is helpful to the parameter measure and the automatic classification of spectra based on spectral lines.