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：2002
卷号：XXXIV Part 3 B
页码：71-74
出版社：Copernicus Publications
摘要：This research work is concerned with the implementation of a shape from shading (SFS) technique for automatically generating a digital terrain model (DTM) using a single digitized aerial photograph of a terrain area with low signal (information) content. The mathematical model for the SFS is established based on the fact that the pixel's gray level variations in image space are proportional to the shading intensity variations of the terrain morphology. The terrain shades in its turn is the function of the illumination intensity and the direction of the incident light with respect to the local surface orientation as well as the incident light direction and the terrain albedo. In this project the Lambertian model is utilized for modeling the terrain reflectivity property. The implemented SFS algorithm is then tested with the simulated and the real data. The simulated data was generated using a predefined bilinear surface and for the real data, an aerial photograph of a smoothed hilly terrain with low information content was chosen. The rmse for the reconstructed surface for the simulated data and the real data were estimated to be equal to ± 3 cm and ± 4 m respectively. This means that the gray shade values are also significantly influenced by the other factors such as the non-uniform terrain albedo, atmosphere, etc., which have not been included into our SFS functional model. It should also be mentioned that our implemented SFS model for the real data was accompanied by a preprocessing stage by which the influential noise was significantly reduced
