{"id":66,"date":"2018-08-02T13:56:14","date_gmt":"2018-08-02T11:56:14","guid":{"rendered":"http:\/\/sigeodev.cerege.fr\/?p=66"},"modified":"2019-10-14T12:51:57","modified_gmt":"2019-10-14T10:51:57","slug":"filtrage-sol","status":"publish","type":"post","link":"https:\/\/sigeo.cerege.fr\/?p=66","title":{"rendered":"Filtrage des points sol dans un nuage de points"},"content":{"rendered":"<p>Diff\u00e9rentes approches et outils peuvent \u00eatre utilis\u00e9s pour filtrer les points appartenant au sol dans un nuage de points et dont pour cr\u00e9er un MNT<\/p>\n<h2>PDAL<\/h2>\n<p>PDAL outil Open-source, on pourra voir ce <a href=\"https:\/\/2016.foss4g-na.org\/sites\/default\/files\/slides\/Filtering%20point%20clouds%20with%20PDAL%20and%20PCL.pdf\">Workshop<\/a> ou diff\u00e9rents exemples sur le <a href=\"https:\/\/pdal.io\/tutorial\/ground-filters.html?highlight=ground\">site officiel<\/a><\/p>\n<h2>LASTools<\/h2>\n<p>avec <a href=\"http:\/\/www.cs.unc.edu\/~isenburg\/lastools\/\">LAStools<\/a>, outil LASGround (payant). C&#8217;est la r\u00e9f\u00e9rence en terme de traitements Lidar.<\/p>\n<ul>\n<li>Utilisation de donn\u00e9es Lidar existante avec classification sol pour extraire le sol de donn\u00e9es de photogramm\u00e9trie : <a href=\"https:\/\/rapidlasso.com\/2019\/04\/09\/using-open-lidar-to-remove-low-noise-from-photogrammetric-uav-point-clouds\/\">https:\/\/rapidlasso.com\/2019\/04\/09\/using-open-lidar-to-remove-low-noise-from-photogrammetric-uav-point-clouds\/<\/a><\/li>\n<li>\n<p class=\"entry-title\">Clean DTM from Agisoft Photogrammetric Points of Urban Scene =&gt; <a href=\"https:\/\/rapidlasso.com\/2018\/12\/27\/scripting-lastools-to-create-a-clean-dtm-from-noisy-photogrammetric-point-cloud\/\">ici<\/a><\/p>\n<\/li>\n<li>et plusieurs autres exemples sur le blog de LASTools : <a href=\"https:\/\/rapidlasso.com\/2014\/06\/13\/dtm-from-dense-matching-points\/\">ex1<\/a> ; <a href=\"https:\/\/rapidlasso.com\/2018\/12\/27\/scripting-lastools-to-create-a-clean-dtm-from-noisy-photogrammetric-point-cloud\/\">ex2<\/a> ; <a href=\"https:\/\/rapidlasso.com\/category\/sure\/\">ex3<\/a> ; &#8230;<\/li>\n<\/ul>\n<h2>CloudCompare<\/h2>\n<p>id\u00e9es en vrac:<\/p>\n<ul>\n<li>utiliser l&#8217;algo Canupo (assez difficile \u00e0 param\u00e9trer).<\/li>\n<li>si on dispose d&#8217;un MNT Lidar, on peut calculer la distance \u00e0 cette surface et filtrer gr\u00e2ce \u00e0 un seuil sur cette distance.<\/li>\n<li>On peut aussi utiliser des seuils min et max si la topo est assez plane et qu&#8217;on a une id\u00e9e de la hauteur de la v\u00e9g\u00e9tation<\/li>\n<\/ul>\n<h2>Agisoft Metashape<\/h2>\n<p>La nouvelle version Metashape propose diff\u00e9rentes approches pour classifier un nuage de points, voir cet article <a href=\"https:\/\/agisoft.freshdesk.com\/support\/solutions\/articles\/31000148866-dense-cloud-classification\">https:\/\/agisoft.freshdesk.com\/support\/solutions\/articles\/31000148866-dense-cloud-classification<\/a><\/p>\n<p>C&#8217;est assez basique comme m\u00e9thode, mais \u00e7a peut aider \u00e0 faire un pr\u00e9-traitement.<\/p>\n<h2>Divers<\/h2>\n<p>post de blog qui r\u00e9f\u00e9rence plusieurs m\u00e9thodes <a href=\"https:\/\/gis.stackexchange.com\/questions\/101786\/determining-bare-earth-dem-from-unclassified-las-file\">ici<\/a><\/p>\n<p>et m\u00e9thode et tuto bien \u00e9crit avec Grass <a href=\"https:\/\/grasswiki.osgeo.org\/wiki\/Processing_lidar_and_UAV_point_clouds_in_GRASS_GIS_(workshop_at_FOSS4G_Boston_2017)\">ici<\/a>, notamment utilisant l&#8217;algorithm MCC<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Diff\u00e9rentes approches et outils peuvent \u00eatre utilis\u00e9s pour filtrer les points appartenant au sol dans un nuage de points et dont pour cr\u00e9er un MNT PDAL PDAL outil Open-source, on pourra voir ce Workshop ou diff\u00e9rents exemples sur le site officiel LASTools avec LAStools, outil LASGround (payant). C&#8217;est la r\u00e9f\u00e9rence en terme de traitements Lidar. &hellip; <a href=\"https:\/\/sigeo.cerege.fr\/?p=66\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Filtrage des points sol dans un nuage de points&#8221;<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-66","post","type-post","status-publish","format-standard","hentry","category-lidar"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/66","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=66"}],"version-history":[{"count":6,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/66\/revisions"}],"predecessor-version":[{"id":315,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/66\/revisions\/315"}],"wp:attachment":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=66"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=66"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=66"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}