论文部分内容阅读
以Landsat-5TM影像为数据源,在对研究区典型地物光谱特征值分析的基础上,利用各水体指数模型之间的关系,探讨了二值化提取水体中阈值确定的其他方法;通过对地物光谱值的分析,发现水体由于泥沙等含量的不同以及深浅的不同,其灰度值变化范围较大,与阴影的重叠较多,而采用谱间关系法,不能确定合适的阈值。提出了加权各波段灰度值并设定阈值去除阴影的方法——加权灰度阈值法,可以有效地去除阴影。研究表明结合水体指数模型法和加权灰度阈值法可以准确地提取水体信息。
Using Landsat-5 TM image as data source, based on the analysis of spectral eigenvalues of the typical landform in the study area, the relationship between the index models of water bodies was used to explore other methods of threshold determination in binary water extraction. According to the analysis of the spectral values of the objects, we found that due to the different sediment content and the different shades, the gray values of the water bodies vary widely and overlap with the shadows. However, the appropriate threshold can not be determined by using the spectrum relationship method. A weighted gray threshold method is proposed to weight the gray value of each band and set the threshold to remove the shadow, which can effectively remove the shadow. The study shows that water body information can be accurately extracted by combining water index model and weighted gray threshold method.