The Visvalingam algorithm metrics, measures and heuristics
This paper provides the background necessary for a clear understanding of forthcoming papers relating to the Visvalingam algorithm for line generalization, for example on the testing and usage of its implementations. It distinguishes the algorithm from implementation-specific issues to explain why it is possible to get inconsistent but equally valid output from different implementations. By tracing relevant developments within the now-disbanded Cartographic Information Systems Research Group (CISRG) of the University of Hull, it explains why (a) a partial metric-driven implementation was, and still is, sufficient for many projects but not for others; (b) why the effective area (EA) is a measure derived from a metric; (c) why this measure (EA) may serve as a heuristic indicator for in-line feature segmentation and model-based generalization; (d) how metrics may be combined to change the order of point elimination; and (e) how Tobler's rule-of-thumb is useful for scale-related filtering of EA. The issues discussed in this paper also apply to the use of other metrics. It is hoped that the background and guidance provided in this paper will enable others to participate in further research based on the algorithm.
|Journal Article Type||Article|
|Peer Reviewed||Peer Reviewed|
|Institution Citation||Visvalingam, M. (2016). The Visvalingam algorithm metrics, measures and heuristics. The Cartographic journal, 53(3), 242-252. https://doi.org/10.1080/00087041.2016.1151097|
|Keywords||Coastline generalization, Visvalingam's algorithm, Effective area (EA) as heuristic, Some applications, Weighted EAs, Scale-related filtering|
|Additional Information||Authors' accepted manuscript of article published in: Cartographic journal, 2016, v.53, issue 3. This paper was previously published as Explorations in digital cartography discussion paper 2, which is available at https://hydra.hull.ac.uk/resources/hull:10596.|
2017-05-26 13650 Visvalingam.pdf