Centre de documentation
scientifique

Visualizing topography by openness: a new application of image processing to digital elevation models / R. Yokoyama in Photogrammetric Engineering & Remote Sensing, PERS, vol 68 n° 3 (March 2002)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 68 n° 3 (March 2002) . - pp 257 - 265 Titre : Visualizing topography by openness: a new application of image processing to digital elevation models Type de document : Article/Communication Auteurs : R. Yokoyama, Auteur ; M. Shirasawa, Auteur ; R. Pike, Auteur Année de publication : 2002 Article en page(s) : pp 257 - 265 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] ligne de visée [Termes IGN] modèle numérique de surface [Termes IGN] niveau de gris (image) [Termes IGN] paysage [Termes IGN] visualisation 3D Résumé : (Auteur) A new parameter, here termed openness, expressing the degree of dominance or enclosure of a location on an irregular surface, is developed to visualise topographic character. Openness is an angular measure of the relation between surface relief and horizontal distance. For angles less than 90', it is equivalent to the internal angle of a cone, its APEX at a DEM location, constrained by neighbouring elevations within a specified radial distance. Openness incorporates the terrain line-of-sight, or viewshed, concept and is calculated from multiple zenith and nadir angles-here along eight azimuths. Openness has two viewer perspectives. Positive values, expressing openness above the surface, are high for convex forms, whereas negative values describe this attribute below the surface and are high for concave forms. Openness values are mapped by gray-scale tones. The emphasis of terrain convexity and concavity in openness maps facilitates the interpretation of landforms on the Earth's surface and its seafloor, and on the planets, as well as features on any irregular surface-such as those generated by industrial procedures. Numéro de notice : A2002-029 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=c3d9a561fdb9e8c34 [...] Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21946 [article]