- Gaussian filter. Implemented by OTB see https:\/\/www.orfeo-toolbox.org\/CookBook\/Applications\/app_Smoothing.html<\/a> or by SAGA see http:\/\/www.saga-gis.org\/saga_tool_doc\/2.3.0\/grid_filter_1.html<\/a><\/li><\/ul>\n\n\n\n
A less common but very recognized and efficient:<\/p>\n\n\n\n
- Mdenoise. It is a despeckle algorithm that can denoise DEMs or meshes. Source code download, install and use see https:\/\/personalpages.manchester.ac.uk\/staff\/neil.mitchell\/mdenoise\/<\/a>. Implemented also by SAGA see http:\/\/www.saga-gis.org\/saga_tool_doc\/2.3.0\/grid_filter_10.html<\/a>. <\/li><\/ul>\n\n\n\n
Examples of such filters on an noisy DEM :<\/p>\n\n\n\n
\n![\"original_dem\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/1_original_dem-1024x855.jpg\")
original_dem<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n ![\"mdenoise_n5_t099\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/4_mdenoise_n5_t099-1024x855.jpg\")
<\/a>mdenoise_n5_t099<\/figcaption><\/figure><\/li> ![\"mdenoise_n10t09\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/4_mdenoise_n10t09-1024x855.jpg\")
<\/a>mdenoise_n10t09<\/figcaption><\/figure><\/li> ![\"mdenoise_n15_t05\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/4_mdenoise_n15_t05-1024x855.jpg\")
<\/a>mdenoise_n15_t05<\/figcaption><\/figure><\/li> ![\"gaussian_circle_r3\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/3_gaussian_circle_r3-1024x855.jpg\")
<\/a>gaussian_circle_r3<\/figcaption><\/figure><\/li> ![\"gaussian_circle_r5\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/3_gaussian_circle_r5-1024x855.jpg\")
<\/a>gaussian_circle_r5<\/figcaption><\/figure><\/li> ![\"lowpass_circle_r5\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/2_lowpass_circle_r5-1024x855.jpg\")
<\/a>lowpass_circle_r5<\/figcaption><\/figure><\/li> ![\"lowpass_circle_r7\"](\"https:\/\/sigeo.cerege.fr\/wp-content\/uploads\/2020\/05\/2_lowpass_circle_r7-1024x855.jpg\")
<\/a>lowpass_circle_r7<\/figcaption><\/figure><\/li><\/ul><\/figure>\n\n\n\n Click on caption to enlarge. r : radius<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Several algorithms can be used to filter DEMs. Most simple and common are: Low-pass filter. Also known as moving average filter. Implemented by many (all) tools, for example in SAGA http:\/\/www.saga-gis.org\/saga_tool_doc\/2.3.0\/grid_filter_0.html Gaussian filter. Implemented by OTB see https:\/\/www.orfeo-toolbox.org\/CookBook\/Applications\/app_Smoothing.html or by SAGA see http:\/\/www.saga-gis.org\/saga_tool_doc\/2.3.0\/grid_filter_1.html A less common but very recognized and efficient: Mdenoise. It is a … Continue reading “Filtering of DEMs”<\/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":[7],"tags":[],"class_list":["post-383","post","type-post","status-publish","format-standard","hentry","category-geo-traitements"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/383","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=383"}],"version-history":[{"count":9,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/383\/revisions"}],"predecessor-version":[{"id":419,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/383\/revisions\/419"}],"wp:attachment":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Mdenoise. It is a despeckle algorithm that can denoise DEMs or meshes. Source code download, install and use see https:\/\/personalpages.manchester.ac.uk\/staff\/neil.mitchell\/mdenoise\/<\/a>. Implemented also by SAGA see http:\/\/www.saga-gis.org\/saga_tool_doc\/2.3.0\/grid_filter_10.html<\/a>. <\/li><\/ul>\n\n\n\n