A topology-preserving polygon rasterization algorithm |
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| Authors: | Chen Zhou Dingmou Li Ningchuan Xiao Zhenjie Chen Xiang Li Manchun Li |
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| Institution: | 1. Department of Geographic Information Science, Nanjing University, China;2. Department of Geography, The Ohio State University, Columbus, USA;3. Securus Technologies Inc, Marlton, NJ, USA;4. Department of Geography, The Ohio State University, Columbus, USA |
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| Abstract: | Conventional algorithms for polygon rasterization are typically designed to maintain non-topological characteristics. Consequently, topological relationships, such as the adjacency between polygons, may also be lost or altered, creating topological errors. This paper proposes a topology-preserving polygon rasterization algorithm to avoid topological errors. Four types of topological error may occur during polygon rasterization. The algorithm starts from an initial polygon rasterization and uses a set of preserving strategies to increase topological accuracy. The count of the four types of error measures the topological errors of the conversion. Topological accuracy is summarized as 1 minus the ratio of actual topological errors to the total number of possible error cases. When applied to a land-use dataset with a data volume of 128 MB, 127,836 polygons, and extending 1352 km2, the algorithm achieves a topological accuracy of more than 99% when raster cell size is 30 m or smaller (100% for 5 and 10 m). The effects of cell size, polygon shape, and number of iterations on topological accuracy are also examined. |
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| Keywords: | Polygon rasterization rasterization error topological error topology preservation topological accuracy |
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