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This can be seen as a preliminary to @Underdark's answer whereby you can clean the topology of the vector layer before generalizing. GRASS has a v.clean function which contains a number of tools to repair the layer such as: snap which 'snaps' lines to the nearest vertex rmdangle which removes any annoying dangles rmdupl which removes duplicated geometry ...


Have you tried using MapShaper? I've found this to be a good way of generalizing polygons; there's also an offline version if you want to download the code. An alternative could be convert this to GeoJson, and then TopoJson which supports "topology-preserving shape simplification" https://github.com/mbostock/topojson


GRASS is topology-aware. You can use v.generalize from the Processing toolbox to simplify polygons and if the input data is topologically correct so will the output.


This is just another idea, by looking at the opposite angle to your question, to find centrelines first as explained one of the methods in here and then search for matching line features. Of course this approach will give robust results if the road lines are at the 'centre' of the polygons. Maybe adding thin ('how thin' is another issue of course) buffers to ...


This is just an idea it would need further experimenting as it may be flawed? How about looking at some sort of ratio value of length/perimeter? Imagine you had a line that is 10m long and has its full buffer which you had buffered out by 2m then the perimeter of the buffer would be approximately 20m. so 10/20 = 0.5. Now imagine you had a line that was ...


It is close to 0 percent likely this photo is in DD. 1) Define the spatial reference of the background image in ArcCatalog. 2) Ensure it aligns with some other dataset (say from arcgis online) in ArcMAP. 3) Create a blank polygon in ArcCatalog. 4) Define the projection of 3 in ArcCatalog. 5) Start a blank mxd in ArcMap. 6) Add (1) the image with the ...

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