期刊
REMOTE SENSING
卷 10, 期 8, 页码 -出版社
MDPI
DOI: 10.3390/rs10081185
关键词
imagery; shadow; shadow detection; illumination; vector; diffuse skylight; high resolution
An alternative technique for shadow detection and abundance is presented for high spatial resolution imagery acquired under clear sky conditions from airborne/spaceborne sensors. The method, termed Scattering Index (SI), uses Rayleigh scattering principles to create a diffuse skylight vector as a shadow reference. From linear algebra, the proportion of diffuse skylight in each image pixel provides a per pixel measure of shadow extent and abundance. We performed a comparative evaluation against two other methods, first valley detection thresholding (extent) and physics-based unmixing (extent and abundance). Overall accuracy and F-score measures are used to evaluate shadow extent on both Worldview-3 and ADS40 images captured over a common scene. Image subsets are selected to capture objects well documented as shadow detection anomalies, e.g., dark water bodies. Results showed improved accuracies and F-scores for shadow extent and qualitative evaluation of abundance show the method is invariant to scene and sensor characteristics. SI avoids shadow misclassifications by avoiding the use of pixel intensity and the associated limitations of binary thresholding. The method negates the need for complex sun-object-sensor corrections, it is simple to apply, and it is invariant to the exponential increase in scene complexity associated with higher-resolution imagery.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据