基于连续消光特征分析的岩石薄片分析系统

A rock thin section analysis system based on continuous extinction characteristics

连续消光是指在正交偏光显微镜下,岩石薄片随载物台旋转而发生消光强弱连续变化的现象。作为人工鉴定岩石薄片的重要依据,提取后的连续消光特征可以用于实现岩石薄片的自动分析。结合数字图像处理技术与聚类划分算法,开发出一套能够分割出孔隙、颗粒轮廓,实现颗粒类别划分,并对结果做定量分析的岩石薄片分析系统。从矿物的消光特征本质出发,连续消光特征提取精确与否是能否有效划分颗粒类别的关键环节。因此,针对系统在连续消光特征提取过程中的消光位对齐与消光基值去除操作分别设置了对照组。以鄂尔多斯盆地某区长6段砂岩薄片在正交偏光镜下的角度域序列图像进行实验,结果表明,所开发的基于岩石薄片分析系统能够提取到更为精确的连续消光特征,且该系统定量分析结果与专业人员鉴定结果基本一致。

Continuous extinction refers to a phenomenon whereby the observed extinction intensity of a rotating rock thin section changes continuously under polarizing microscope observation.As an important reference for thin section identification,the extracted characteristics of continuous extinction can be used in the automatic thin section analysis.Combining digital image processing technology and clustering algorithm,we developed a thin section analysis system for grain segmentation,grain identification and quantitative data analysis.How to precisely extract the characteristics of continuous extinction-based on the extinction characteristics of minerals-became the vital part of grain identification.Therefore,we set up the control groups for extinction position alignment and baseline correction during the extraction operation.The resulting angular domain sequence images of sedimentary rock thin section under crossed polarizer show that the extinction position alignment and baseline correction contributed to more accurate continuous extinction characteristics,and the results of thin section analysis by our method matched those by expert evaluation.