基于相位一致性的太阳图像低对比度特征提取研究

项目名称： 基于相位一致性的太阳图像低对比度特征提取研究

项目编号： No.11463003

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 冯松

作者单位： 昆明理工大学

项目金额： 62万元

中文摘要： 太阳观测图像中存在大量的低对比度特征结构。它们具有局部相对强度小、结构边缘模糊的特点，因而难以运用传统的基于强度和梯度两个基本量的图像处理方法进行准确的特征结构提取。近年来的研究发现，相位一致性也是一种描述图像底层特征的基本量，并且对特征强度和对比度的测度具有不变性。我们的实验表明，与传统的识别方法相比，基于这一理论的处理方法在太阳图像低对比度特征结构提取上有较为明显的效果。本项目以太阳黑子本影区域的本影点和本影闪耀，以及冕环的形态特征作为具体的研究对象，进一步深入研究如何将相位一致性理论和方法应用于多种太阳观测图像，以便有效地提取低对比度特征结构。本项目拟解决的关键技术包括：滤波器的设计以及方向的选择、噪声补偿机制、特征提取与所测量物理量的联系等。项目特色和创新在于将与强度和梯度图像处理方法完全不同的底层特征描述- - 相位一致性引入到太阳图像处理中。本项目研究成果预计将有广泛的应用价值。

中文关键词： 图像处理；低对比度；相位一致性；特征提取

英文摘要： There are abundant low-contrast phenomena in solar observations. Traditional method of feature detection using intensity or/and gradient threshold is extremely diffcult to accurately identify the low-contrast features, because they appear as blurred edges and relatively low intensity values. Phase Congruency (PC) is a novel method describing low-level features of image, which is perfectly combined local image intensity with phase in frequency domain. It is invariant measure to image luminance, contrast, intensity, and image magnification. The characteristics can solve the problem that traditional method of image processing excessively depends on image intensity or/and gradient threshold.Our expriments show that the feature detection with PC is more efficient than traditional methods with image intensity and gradient in respect of low-contrast feature extraction. We will research the low-contrast features with sunspot umbra and conoral loops of off-limb because they exhibit typical features of lower contrast than adjacent features.We focus on solving challenging technical problems in obtaining phase characteristics, noise compensation and description of ROI using PC. One of the innovative points of the proposal is that we lead the PC technique to sloar image processing in order to solve the problem of low-contrst feature detection. The goal of this proposal is to increase the identification accuracy of low-contrast features and the robustness of the algorithm from a new perspective, and to reduce the negative effects of subjective factors in solar image processing. Finally, the proposed research may be applied to other features extraction from solar images.

英文关键词： Image Processing;Low-contrast;Phase Congruency;Feature Detection