中国科学院云南天文台机构知识库

太阳图像中包含了各种不同尺度、不同结构以及不同亮度的活动现象,它们都是实测太阳物理的研究目标。这些活动现象经常会使图像显示的跨度过大,导致图像暗弱细节结构被隐藏。对于地基望远镜,由于地球大气对观测数据的影响,也造成图像整体对比度下降。这些都不利于人们直观地从图像中发现感兴趣的太阳活动现象或结构特征。针对这些问题,运用直方图规定化的方法对实测太阳物理中常遇到的几类观测目标图像(太阳极紫外像,太阳光球黑子像,色球活动区像以及色球日珥像)进行处理,通过瑞利分布、双高斯分布以及三重瑞利混合分布等直方图形式实现对这几类图像的显示对比度增强。通过对空间望远镜SDO的极紫外太阳像和1m新真空太阳望远镜(New Vacuum Solar Telescope,NVST)的色球和光球像的处理展示了该方法的处理效果。结果表明,方法可以有效提高各类太阳活动现象的显示度,便于人们在研究初期发现感兴趣的活动现象。

The solar image contains a variety of different scales, different structures and different brightness active phenomena. These phenomena often causes the span of the image is too large, resulting in hidden of faint detail structures. Furthermore, for the ground-based telescope, because of the influence of the earth atmosphere on the observations, the overall contrast of the image is decreased. These factors are not conducive for people to view the features of interest from images intuitively. To solve these problems, this paper uses the histogram specification method to deal with several targets (solar extreme ultra-violate image, sunspot, solar Hα active region and solar prominence) commonly encountered in solar observations. In this paper, the Rayleigh distribution, Double-Gaussian distribution and Triple-Rayleigh distribution is proposed to realize the contrast enhancement of these images. The effect of this method is demonstrated by the processing of solar ultraviolet images from Atmospheric Imaging Assembly on the SolaDynamics Observatory (AIA/SDO), solar Hα image and sunspot image from New Vacuum Solar Telescope (NVST). The results show that this method can effectively improve the visibility of these solar active phenomena, and it is convenient for people to find interesting active phenomena in the early stage of the study.