Questions tagged [skeleton]

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19
votes
2answers
9k views

Finding tunnel center line?

I have some map files consisting of 'polylines' (each line is just a list of vertices) representing tunnels, and I want to try and find the tunnel 'center line' (shown, roughly, in red below). I've ...
16
votes
5answers
5k views

Simplifying polygons to linestring?

I would like to simplify some polygons that represent rivers into linestrings. I assume that holes in polygons can be omitted. Anybody has some good idea how to simply do it? It would be nice, if it ...
12
votes
2answers
4k views

How to compute Straight Skeletons using Python?

Is there a Python package which provides an implementation of a Straight Skeleton algorithm? I'm aware that the open source (C++) project CGALcontains an implementation but it seems like cgal-...
8
votes
2answers
2k views

Skeletonize vectors in QGIS/Python

I am trying to find a tool to create a skeleton of a large vector dataset using QGIS and its bundle. It should be directly programmatically callable through Python or commandline (QGIS, GRASS, OGR etc....
6
votes
1answer
404 views

Travel planning - Finding farthest points of a polygon

I’d like to organize a tour around the lake with 2 objectives: maximise the length of shores to view minimise travel distance In order to do so I can: Pick 2 most remote points on the lake in ...
5
votes
2answers
518 views

how to get a low level road network from openstreetmap data?

I've extracted the road network of a city from openstreetmaps (filetype: osm). One part of the road networks look like this: However, there are too many details in this data. I'd like to represent ...
4
votes
1answer
4k views

Create centreline from a polygon [duplicate]

I am working on a project to create a centerline from a polygon automatically. The user select a polygon and click a button, the centerline will create for him. I have tried the build-in function “...
3
votes
0answers
144 views

need Matching Algorithm which takes graph Topology into account

Problem: I have a problem (illustrated below) with matching two datasets. On the left I have a GIS containing drain network data (in blue), including diameter, length and topology information (from- ...
1
vote
1answer
291 views

Simplifying multiple lines to create central axis?

I have a layer with railway lines, downloaded from OpenStreetMap. Every single track is represented separately, so at trainstations, you have several parallel lines, as well as sidelines that lead to ...
1
vote
0answers
43 views

How to use Voronoi.Skeleton in QGIS

My purpose is to make a central line from a polygon. For this I use the skeleton algorithm from a polygon, but I did not manage to get a line. I draw the polygon. I launch the program. It doesn't ...
1
vote
1answer
143 views

v.voronoi.skeleton error

Recently, I was looking for way to skeletonize buffer and besides solution with PostGIS and Postegre solutions there is algortihm v.voronoi.skeleton. I have tried to use it with different road/rail ...
0
votes
1answer
296 views

removing spurious lines in raster before or after vector conversion?

I'm looking for a feature/function in either python opencv/ndimage/gdal/etc. or qgis/saga/grass that will help clean up a skeletonized image that I'd like to vectorize into a shapefile of lines/...
0
votes
0answers
26 views

SAGA Tools not working in QGIS 3.6.1 with GRASS 7.6.1

I installed QGIS 3.6.1 with GRASS 7.6.1 As I am trying to get administrative borders from old map. I did some pre-processing in GIMP and already selected the borders with treshhold functions and so on....