期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2003
卷号：XXXIV-5/W12
出版社：Copernicus Publications
摘要：We are digitizing a whole terrain and ruined buildings of a medieval harbor city on the island called Gemiler Island, as 'Digital Gemiler Island project.' To make textured 3D models of the ancient buildings, we have measured shapes of some of the buildings on the site with a laser range scanner and taken high-resolution images for textures with digital cameras. Since we've taken the photos in the daytime, the texture images are affected with shadows and shadings by the sunlight. To render the 3D model of the buildings on arbitrary lighting conditions, these effects of shadows and shadings must be removed from the images. Although there are several techniques for removing shadows and shadings from images, most of them need several images with different lighting conditions for each scene. However, taking images several times with the same camera positions and different lighting conditions is very time consuming. In Digital Gemiler Island project, we can use the globally registered 3D model of the buildings, which is measured with 3D laser scanner and GPS, the direction of light (the sun), and camera pose information for each images. In addition, variations of the surface materials of the ruined buildings are very limited. In this paper, effects of shadows and shadings are removed taking advantages of these characteristics. We assume a parametric re.ection model and estimate the parameters of the model fitting the model to the images, by which separating effects of shadows/shadings from re.ectance. The method needs only single image for each scene
关键词：Shadow Removal; Shade Removal; Re.ection Model
