Smoothing contour lines of hydrographical maps: an optimised approach
Hennau, M.; De Wulf, A. (2006). Smoothing contour lines of hydrographical maps: an optimised approach, in: Evolutions in hydrography, 6th - 9th November 2006, Provincial House Antwerp, Belgium: Proceedings of the 15th International Congress of the International Federation of Hydrographic Societies. Special Publication (Hydrographic Society), 55: pp. 199-201 In: (2006). Evolutions in hydrography, 6th - 9th November 2006, Provincial House Antwerp, Belgium: Proceedings of the 15th International Congress of the International Federation of Hydrographic Societies. Special Publication (Hydrographic Society), 55. International Federation of Hydrographic Society: London. 234 + cd-rom pp., more In: Special Publication (Hydrographic Society). Hydrographic Society: London. ISSN 0309-8303, more |
| Keywords | Aquatic sciences > Marine sciences > Earth sciences > Oceanography > Physical oceanography > Hydrography
Audiovisual materials > Graphics > Maps
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| Abstract | Perhaps the most classic way to represent 3D-objects, like the DTM from a hydrographical survey, on a 2D medium is by generating contour lines. The sight of an unsmoothed contour map can be too rough and is often rejected by the map users, especially when a shelving surface is being represented. However, many users object to smoothing on grounds that smoothed contours do not honour the linear character of the source data. Therefore, the application of smoothing procedures for aesthetic purposes should be in respect with the geometrical properties of the source data. A popular method to smooth contour lines consists in smoothing each contour independently of the rest. A second approach engages the distillation of contour lines from smooth surface patches. An eclectic procedure has been worked by A. Christensen out to combine the advantages and minimize the drawbacks of both approaches. Furthermore we have refined the eclectic method by inserting optimisation algorithms into the procedure in order to smooth in an adaptive way and to increase the geometrical integrity of the contours. |
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