# Christopher M. Gold

It's not surprisingly when entering this site to get the book. One of the popular books now is the digital terrain modeling principles and methodology. You may be confused because you can't find the book in the book store around your city. Commonly, the popular book will be sold quickly. And when you have found the store to buy the book, it will be so hurt(More)
We wish to extract the topology from scanned maps. In previous work [15] this was done by extracting a skeleton from the Voronoi diagram, but this required vertex labelling and was only useable for polygon maps. We wished to take the crust algorithm of Amenta, Bern and Eppstein [3] and modify it to extract the skeleton from unlabelled vertices. We find that(More)
• Algorithmica
• 2001
We wish to extract the topology from scanned maps. In previous work [GNY] this was done by extracting a skeleton from the Voronoi diagram, but this required vertex labelling and was only useable for polygon maps. We wished to take the crust algorithm of Amenta et al. [ABE] and modify it to extract the skeleton from unlabelled vertices. We find that by(More)
• 7
• Spatial information may be viewed in two ways: as coordinates measured with a ruler along imaginary axes; or as the adjacency relationships between objects. The former has been the most common historically, but the latter appears more relevant to the handling of spatially distributed objects in a computer. The interpolation problem, as implemented using(More)
• International Journal of Geographical Information…
• 2001
Models of spatial relations are a key component of geographical information science (GIS). EŒorts have been made to formally de ne spatial relations. The foundationmodel for such a formal presentation is the 4-intersection model proposedby Egenhofer and Franzosa (1991). In this model, the topological relations between two simple spatial entities A and B(More)
• GeoInformatica
• 2000
Generating terrain models from contour input is still an important process. Most methods have been unsatisfactory, as they either do not preserve the form of minor ridges and valleys, or else they are poor at modelling slopes. A method is described here, based on curve extraction and generalization techniques, that is guaranteed to preserve the topological(More)
• GIScience
• 2006
Voronoi diagrams are widely used to represent geographical distributions of information, but they are not readily stacked in a hierarchical fashion. We propose a simple mechanism whereby each index Voronoi cell contains the generators of several Voronoi cells in the next lower level. This allows various processes of indexing, paging, visualization and(More)