Hell again: Thanks for the help I followed youre recommendations and use base layer for openstreet map and edited for my needs. None the less I will keep trying to develop this in spatial analysis due that Im working with drone collected data and a lot of areas (whole municipalities) to develop infrastructure maps.
I will keep posted on progress. Thanks for the help. Elvin Roldán > On Apr 18, 2019, at 12:04 PM, Kirk Schmidt <k...@nortekresources.com> wrote: > > Hallo Elvin: > > This would be a bit tricky as roads are not created equal. A paved road and > associate paint is very different from a cobblestone or gravel road. Add > shadows from trees, buildings and rock cuts and the complexity increases. > If you used a supervised classification you would end up with clusters of > pixel polygons or pixel points that would not be very consistent. The level > of work required to edit and simplify these would be very time consuming. > It is for these reasons that original line features such as roads where > digitized as simple vectors. As bernd suggest below, existing vector data is > available for most areas and it is simply a matter of locating and accessing > these sources. > > Kirk > >> On 4/18/2019 12:10 PM, Bernd Vogelgesang wrote: >> Hi Elvin, >> >> I do not know of any trick how to extract a road network from images besides >> a trained image classification model. But may the question be allowed why >> you can't just use the OpenStreetMap data directly? >> >> Cheers, >> Bernd >> >>> Am 18.04.19 um 15:12 schrieb Elvin Roldan: >>> Hello: >>> >>> >>> >>> I’m writing because I’ve been a long time user QGIS and really appreciate >>> all the work that has been put to it and all the initiatives to continue to >>> evolve and maintain it as an important open source GIS system. >>> >>> My question is aim does anybody know how to extract a road network using >>> spatial analysis tools within QGIS. I want to extract all roads from aerial >>> images to convert to vectors (polylines or polygons) to do various analysis >>> involving the existing road network. >>> >>> If anybody can point me in the right direction I would appreciated. >>> >>> Thanks. >>> >>> Elvin Roldán >>> >>> >>> >>> _______________________________________________ >>> Qgis-user mailing list >>> Qgis-user@lists.osgeo.org >>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >> >> >> _______________________________________________ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > -- > Kirk Schmidt, MScF, BScF, RPF > General Manager > Nortek Resource Solutions Inc. > RR # 1 > Thorburn, NS > B0K 1W0 > Tel (902) 922.3607 > Email: k...@nortekresources.com > Web: www.nortekresources.com > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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