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Questions tagged [generalization]

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2
votes
1answer
126 views

Display multiple lines as one line in QGIS

I am working with the OSM Dataset and can´t find a way to display rails in a proper way. In a big scale the rails are displaying fine but as soon the lines begin to overlap in a smaller scale I don´t ...
0
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0answers
73 views

Generalizing railways from OpenStreetMap using ArcGIS Desktop?

I have dataset of railways from OpenStreetMap. It is really detailed. But i want to make generalization for map scale 1:500 000: remove small details of the railways and short branches. I`ve used ...
2
votes
0answers
48 views

Wang's Bend Simplify in QGIS

I am looking for an alternative to ESRI's Simplify Polygons - Bend Simplify method (I only have a Basic License). Is there an existing QGIS plugin which supports this specific polygon simplifying ...
3
votes
2answers
128 views

Automatically fill gaps and merge freshly generated polygons with the longest adjacent polygon

I get polylines automatically generated from AutoCAD from a colleague. Converting them into polygons with QGIS 3.6, I find out some sliver polygons and gaps in between, as shown in the picture below : ...
0
votes
0answers
23 views

Reclass raster map areas smaller than specified area size

I need to reclassify raster areas smaller than 100m2 (0.01 ha) to new ones. r.reclass. area from GRASS GIS does the job for some raster sizes, but simply stucks/doesn't work on bigger ones (54000 x ...
1
vote
1answer
72 views

“Average” of two lines

I have a dataset of pairs of parallel linear features (railway tracks) and I need to simplify each pair into its central/median line. This could be achieved by computing a skeleton as suggested in ...
2
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0answers
64 views

Generalizing / simplifying multipolygon in PostGIS without missing polygons?

By following the rules from this site, I got the output but some polygons do not come within the simplified polygon. I think the problem is with topology. Is there any solution?
0
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0answers
55 views

Simplify a polyline/polygon using a threshold on maximum number of vertices in PostGIS?

The various simplification functions in PostGIS (e.g. ST_Simplify) uses a tolerance parameter for the maximum allowable deviation of the generalized shape from the original. My question is: Is there ...
2
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0answers
23 views

Conditional Expanding in ArcGIS Desktop?

I would like to reclassify a LC map given some conditional rules (raster with 8 classes total). Using the illustration, I would like to expand the green pixels (two distinct classes) on the white ...
1
vote
1answer
41 views

v.generalize in QGIS throwing “Unable to create table” error

I am trying to smoothen few polyline shapefiles using v.generalize in QGIS 3.4. But it's not working. Even i tried the same in QGIS 2.18. Getting the same error. Tried the same process in GRASS 7.4.2....
1
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0answers
36 views

How to remove complicated shapes in ArcGIS - generalization [duplicate]

What can be the way of simplifying polygons in ArcMap? I have a shapefile with buildings and I have to make them as simple as it's possible. I used already some tools, like: dissolve, union, ...
1
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0answers
46 views

Convex boundary of polygon [closed]

Is there any tool that can help me with my problem? I have polygons looking like this : And what I want, is to simplify or gain convex boundary of such polygons. I tried Simplify Polygon in ArcMap, ...
2
votes
2answers
197 views

Cartographic generalization: Dissolve “neighbour” / bordering polygon objects in QGIS

I have a polygon layer with buildings for the area of the whole city. My question is how to dissolve/aggregate/merge only those buildings, that are "neighbours", in a sense that they share at least ...
0
votes
1answer
60 views

Avoiding thin parts of polygons using ArcGIS Desktop?

I've used Simplify Polygon with 'Maximum Allowable Offset' 250m, and then Aggregate Polygons with 'Aggregation Distance' also 250m (opposite order also tested). Still I have thin parts of polygons as ...
5
votes
1answer
71 views

Getting WHERE statement to work in v.generalize?

I have a shape (its topology is terrible but I don't think it's the problem). I'm trying to simplify it to reduced it's size using v.generalise. I succeeded at reducing the whole shape but I ...
3
votes
1answer
48 views

Is there a built in way to reduce the amount of points in an IElement

I have a polyline element and I want to reduce the number of points (vertices?) that make up the line. I know it will make the curved sections jagged and that is fine. I just want to control (perhaps ...
46
votes
5answers
34k views

What raster smoothing/generalization tools are available?

I have a DEM that I would like to smooth or generalize to remove topographic extremes (chop off peaks and fill-in valleys). Ideally, I would also like to have control over the radius or level of "...
1
vote
0answers
80 views

How to generalize shape with PyQGIS without much Distortion in the shape?

I was trying to generalize the the inner boundaries of the polygon. Looking for a PyQGIS solution for that any other possible python solution will be fine. I tried convex hull and simplify geometry ...
1
vote
0answers
25 views

Smooth Data Values Across Geographies with Zero Population

Looking to fill in gaps through generalizing a population count across U.S. counties. I.e., if a county has 0 population, but is surrounded by 5 non-zero counties, then change the 0-population county ...
1
vote
1answer
51 views

Remove small interstices on the edges of a polygone

How can I remove the white interstices on the edges (and interior) of a polygone or polyline, as represented in the first figure below? I want to get smooth and continuous edges, capturing the global ...
1
vote
1answer
483 views

Merging unconnected line segments using ArcGIS Desktop?

I am looking for a way to connect line segments that are unconnected. It is a shapefile for a network of rivers and all the lines are slightly disconnected. Is there something like aggregate ...
1
vote
1answer
142 views

How to generalize QGIS 3.0 Model so that I can install on multiple computers without setting up on every computer?

I am trying to create a model to work on multiple computers with little editing. I am working in QGIS 3.0. I am trying to get the model to first set the style for the layers based on a predefined qlr. ...
1
vote
0answers
481 views

Generalize Polygons in QGIS 3.0

I would like to use different generalization tools for polygons in QGIS 3.0. Especially for aggregation, simplifying and smoothing. Back using QGIS 2.8 there were the following possibilities: ...
1
vote
0answers
80 views

Speeding up workflow of generalizing OpenStreetMap road data?

Whenever I want to use OSM data for medium scale maps (e.g. 1:200.000) I run into problems. On the screenshot below one can see the orange street that goes from north to south. It has the attribut ...
37
votes
5answers
53k views

Smoothing/generalizing polygon in QGIS?

Is it possible to smooth or generalize a polygon in QGIS, perhaps by using a plugin like the generalizer-plugin for lines? I could convert my polygons to lines, smooth them and convert them back to ...
2
votes
0answers
183 views

Building footprint polygon simplification / generalisation

I'm looking for implementations of polygon simplification algorithms that preserve topology and overall rectilinearity. The input data is building footprints which often have squarish protrusions and ...
22
votes
3answers
11k views

Seeking Generalisation Strategies for Building Outlines in PostGIS?

I have a dataset of building footprints vectorised from a raster dataset. The dataset is currently just a vector representation of the raster data. I would like a polygon dataset that only has ...
0
votes
1answer
51 views

Reducing filesize for landslide susceptibility map

I have a large .tif file that I would like to reduce to under 15MB (currently 650MB). The file shows 3 zones of landslide susceptibility (see pic below). I am processing it so that I can upload it to ...
7
votes
1answer
3k views

QGIS equivalent to ArcGIS Aggregate Polygons?

I am looking for a tool in QGIS 2.40 that performs the function ArcGIS refers to as Aggregate Polygons. Basically it takes a group of polygons within a specified distance and creates a concave hull ...
1
vote
0answers
256 views

How to reduce the density of points based on zoom level

I have a Polyline like the one shown in the example, representing the path of a vehicle. GeoJSON markers show the vehicle's position over time. How can I reduce the density of the markers when the ...
1
vote
1answer
80 views

Options for generalizing raster?

I have a DTM raster which has too high a spatial resolution for my intended use, and I need it more generalized. Can't put my finger on how much more, but considerably more. My first thought was to ...
1
vote
1answer
193 views

Generalising Rasters using .ovr pyramid data?

I have to produce some lower spatial resolution rasters from a large number of very big geotiffs (c.800GB). It occured to me that since I've produced the pyramid overviews using GDAL already I could ...
25
votes
10answers
6k views

Existing solutions to automate generalisation/simplification of geographical data?

I am looking for existing solutions (softwares, libraries, methods, etc.) to automate the generalisation/simplification of geographical data as presented there, and also there. Do you know and use ...
2
votes
2answers
423 views

How to smooth a raster in a rectangular fashion using gaussian blur?

How do I adjust the code for the Gaussian Blur posted in the thread: What raster smoothing/generalization tools are available? to retain the resolution/gradients in the y direction and blur only ...
0
votes
2answers
208 views

What is the process by which ONS creates “Generalised” and “Ultra Generalised” Clipped Boundary shapefiles?

The ONS (Office for National Statistics) in the UK makes available a large number of shapefiles based on geocoded statistical data sets and admin/demographic boundary shapefiles. These are deposited ...
1
vote
0answers
135 views

Line generalization not working

After having installed the plugin - Cartographic Line Generalization - I try to open the tool in the Plugins menu and receive the following error: AttributeError: 'NoneType' object has no attribute '...
1
vote
1answer
260 views

How to generalize polygones in QGIS

I am working with vectorized greyscale images converted into polygon layers by the QGIS vetorize tool. Currently I am using a rather long way to get rid of small polygones. I convert the polygons ...
2
votes
1answer
457 views

Raster smoothing/generalisation in FME

I'm trying to find an equivalent in FME to the Majority Filter in ArcGIS (http://desktop.arcgis.com/en/arcmap/10.3/tools/spatial-analyst-toolbox/majority-filter.htm), I've had no success this far... ...
1
vote
1answer
160 views

Geoserver (automatic labeling generalization) [closed]

I am a Master student looking to do my thesis in cartographic labelling using GeoServer. The thesis topic will be something like "Cartographic Labelling in Real Time Mapping using Web Services. I am ...
3
votes
1answer
553 views

Is it possible to simplify orthogonal polygons with OpenCarto Java Library?

I want to know if simplification of orthogonal polygons can be done with OpenCarto Java Library. If yes, does it have any API documentation?
1
vote
0answers
29 views

Square polygons that are covered by trees

I would like to know if there is a way to square polygons? I would like to calculate the total square meters of houses. I have extracted the buildings as well as tree coverage but I am unable to get ...
4
votes
3answers
337 views

Enlarge/roughen the Vector Size of Tiles

I'm currently running a GeoServer service and my task is to make the vectors rougher than they are right now. I really don't know where and how GeoServer processes the data from the database and how ...
1
vote
1answer
97 views

Problem with low quality tiff

I have the problem with low quality raster. Now it looks like this: a busy cat http://iv.pl/images/53039057684486451032.png I would like to change this to looks like this: a busy cat http://iv.pl/...
3
votes
1answer
214 views

Jagged Polygon Edge Generalization in ArcGIS Desktop?

I have a polygon which the edge is quite normal when zoomed out: But when zoomed in this is how the edge looks like (jagged) because it was converted pixel by pixel from a raster, is there a ...
1
vote
1answer
129 views

Generalizing road polylines?

I have a dataset of road lines obtained from digitized aerial imagery and I want to automate the generalization procedures using arcGIS model builder. I am using the ArcGIS 10.3 desktop suite. I have ...
3
votes
0answers
59 views

What amount should be kept on map? [closed]

I am generalizing geological map, for initial process I am dealing with small polygons which are less than minimum separability unit and try either remove them or enlarge. For the first step I am ...
22
votes
3answers
10k views

Performing Raster Noise Reduction and Edge Smoothing?

I have a raster image like this I want to delete the isolated noise point and smooth the edge (say the white single points, and I want the edges of the entity look smooth). How can I do this in ...
18
votes
3answers
2k views

How to generalize SpatialPolygons and conserving topology in R?

I would like to generalize a SpatialPolygonsDataFrame in R to make plotting more efficient. The polygons I have result in huge pdf plots that are slow to load and hard to integrate into a document. ...
0
votes
1answer
528 views

How to set a maximum amount of features to be drawn in every zoom level

I want to apply a form of generalization/specialization to my OpenLayers map. Is there a way to set the amount of WFS features to be rendered based on the zoom level? In GeoServer you can set the ...
3
votes
1answer
1k views

Collapsing multiple lines into single line?

I need to create a route (line) feature class from another feature class that contains multiple lines making up the same route. pic 1 shows the original feature class with the multiple lines. pic 2 ...