Generalisation is the simplification operation applied on spatial data when their representation scale decreases.

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5
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1answer
98 views

How to cartographically generalise buildings/settlements in QGIS?

I have a set of buildings in a polygon layer which I'm going to use in a 50k map. Since the buildings are tiny I cannot show the actual form of the building, instead I'm taking the centroid of the ...
1
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0answers
28 views

How to generalize a raster with noisy edges with ArcGIS Desktop?

I'm trying to generalize a raster to get clean edges (see sample and "optimal" result below). However the borders bleed into each other to a rather high degree. I hacked away at the raster using ...
2
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0answers
46 views

Avoiding edges using GRASS generalization?

I'm trying to process the national wide land cover data into vector polygons. In order to be quick I separate the data into several tiles and process them in parallel. process flow is : 1. v.in.ogr ...
3
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2answers
73 views

Simplify/generalize Polygons and keep topology of different layers PostGIS/QGIS

i have some polygons of a country, states, districts, communities and i want to simplify the geometry. i already simplified the geometry of each layer but afterwards of course it doesnt fit with the ...
1
vote
1answer
45 views

Problem with low quality tif

I have the problem with low quality raster. Now it looks like this: I would like to change this to looks like this: Im using ArcGIS, ArcScan. After some work with photoshop and reclassify with ...
2
votes
1answer
54 views

Generalizing exact location of certain data points using Carto CSS?

I am dealing with some sensitive data for which providing a high resolution of accuracy of the location would be detrimental. However, the general location is not sensitive and useful to share. I ...
2
votes
1answer
66 views

How to produce outline of a coastline?

I have polygon dataset containing quite a complicated coastline. How can I produce an outline of that coastline? Please see the image: my dataset is in green and the coastline I need to get is in ...
0
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0answers
35 views

Geological map generalization polygon aggregation

I am working on generalization of Geological maps and the first thing I am wondering about is aggregation of separate patches that may have same class and which are closely situated to each other. ...
1
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1answer
36 views

Creating fishnet from thematic polygon data?

I need to create a regular grid containing attributes from other thematic data from ecological data. I am in effect creating a homogenous polygon raster and adding information from another dataset ...
1
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0answers
47 views

Combine two parallel lines to one with postgis

In OpenStreetMap, a highway=motorway consists out of two parallel lines, each representing one direction: On a professional map the two lanes get combined to one single line and drawn with a middle ...
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0answers
65 views

QGIS: automatic generalization

I'm trying to generalize my line features with QGIS. I've tried the "Generalizer"-Plugin, but can't get the results i want. I'd like to generalize my line as shown in the image. I've tried the ...
2
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2answers
101 views

Collapse dual lines to centerline doesn't exist in ArcGIS Pro?

I have ArcGIS Pro build 3308 (Ver. 1.1) and wish to collapse two parallel lines into one, however it appears that this function no longer exists - I have also tried using python for this and received ...
1
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2answers
598 views

How to remove unnecessary vertices

I have over sampled polygons that I need to simplify, without changing the shape. basically, I want to reduce the number of vertices, by eliminating the ones that are useless and have the polygons ...
0
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0answers
38 views

Generalize a selected part of shapefile

I see v.generalize takes the whole shapefile as input, but is there a way in QGIS to generalize/smooth selected part of a shapefile? I will select the part in Node Tool and then use v.generalize tool. ...
3
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1answer
223 views

Collapse multiple lines into a 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 ...
0
votes
1answer
104 views

Simplifying polygons in ArcGIS considering contains-one-point topology rule?

I want to simplify polygons using the "Simplify Polygon (Cartography)" tool in ArcGIS 10.2. Additionaly there is one point in each polygon and this condition should still be fulfilled after ...
0
votes
1answer
56 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 Open Layers 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 ...
7
votes
1answer
134 views

What do you call this non-hole edge condition?

After generalizing or simplifying polygons, you often get legitimate holes in polygons, which are separate parts and can be filled. But what is the correct term for this triangular shape? It is an ...
1
vote
1answer
84 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 ...
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2answers
35 views

How to find “empty” buffer?

So I have lines(road network) and buffers around them. I need to find "empty bufers" whose lines is missing (pic below). Lines have attributes of buffer width, but it is incorrect in some cases (does ...
2
votes
1answer
347 views

Why are my polygons automatically simplified/generalised when merging them in ArcMap 10.2?

I am creating a small land use map, as an exercise for visual image interpretation. I created a shapefile and started digitising polyogons with the polygon tool. The problem is that some of my ...
4
votes
1answer
612 views

How to reproduce Smoothing from Generalizer Plugin in v.generalizer in Processing Toolbar using QGIS?

I´d like to reproduce the smoothing operations done with the Generalizer Plugin inside the v.generalizer Toolbox so I can use them on a polygon layer instead of only on a line layer. I tried ...
6
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0answers
126 views

Alternative to Delete Polygons And Extend Lines of Production Mapping? [closed]

Maybe someone knows an alternative for the Delete Polygons And Extend Lines (Production Mapping) tool or a simple way to achieve the same result but without requiring a Production Mapping license?
0
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2answers
136 views

v.generalize on massive vector data

I have a contour line file that covers the most part of north italy (shape is 0,6 gb) and I want to use v.generalize (snakes algorithm) on it. Because of the large file size, if I use Grass 6.4.3 I ...
1
vote
1answer
107 views

How to simplify a multiline geometry in QGIS?

I'm trying to simplify my shapefile, which uses a lot of vertices to represent curvatures, by using the Generalizer plugin. But no matter what threshold I use for Douglas algorithm, it still includes ...
5
votes
1answer
202 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
1answer
80 views

Generalize lines with specific points

It's been a while since I was here. I have this problem now. I have electricity line feature class and point feature class intersecting line features. What I need to do is simplify this line feature ...
5
votes
2answers
161 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 ...
6
votes
1answer
400 views

Competing approaches to line & polygon simplification

There seems to be a few theoretical options around at the moment for geometric simplification. Douglas–Peucker seems the most established, followed by Visvalingam's approach (used by d3.js). Now ...
4
votes
1answer
517 views

How to maintain right-angles when buffering?

When buffering some polygons I am trying to avoid the curved buffered area like this: I'm trying to do thins within an FME workbench but if someone knows how its done in other software that would ...
8
votes
4answers
2k views

How to generalize a point feature class

I have a point featureclass with a point for every 25cm - in Total 400,000 Points. I would like to reduce this resolution to one point every Meter. How could I instruct ArcGIS Advanced(ArcInfo) to do ...
2
votes
0answers
101 views

Is there a way to build topology and work with topology relations in PyQGIS?

Is there a way to build topology and work with topology relations in PyQGIS? I'm asking because I need to run some custom generalization algorithms on my data, and I need to preserve topology. ...
2
votes
2answers
304 views

Merge point features within a given radius [duplicate]

I have a file in QGIS with 5000 points. Some of the points are really close to each other (5m). How can I cluster the point features to one point feature if they are within 5m? The new points should ...
0
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0answers
89 views

How to generalize road network to be exact angle to each other?

I need to generalize a road network to be an exact angle to each other, we are talking about parallel streets like New York. The thing is that when you generalize, you do it per feature. I am trying ...
3
votes
1answer
345 views

Flatten GIS data to a schematic

I want to take a network of roads and lanes and reduce them to a schematic that shows their relationships but not their geographic shape. A similar concept has been used for the London Underground ...
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0answers
50 views

Condensing sparse geocodes to weighted Geo-Circles?

I have a dataset comprising 3 million records having latitude and longitude information associated with them. I want to condense it to form few thousands Geo-Circles, with radius and weight depending ...
6
votes
6answers
880 views

Tool/Algorithm for generalizing OSM-Files for printing maps

Is there a tool or algorithm to (topological) generalizes OSM-shapes? I would like to build a printable map in different scales. In the image below you can see the same divided road (yellow) at ...
2
votes
1answer
200 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 ...
1
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0answers
169 views

When digitizing Lines, vertices are automatically generalized when finished feature

I am creating lines(feature class) and when the feature is finished Arcmap 10 will automatically generalize/smoothens the line. Is there any reason why this is happening? is this a bug of ArcMap 10? ...
2
votes
1answer
197 views

filter / generalize elevation points on the basis of some conditions

I wanted to generalize many elevation points in a rectangular area (about 700 square km). I need to take about 3 points for square km. These points must satisfy some conditions: One of these ...
7
votes
2answers
2k views

Tips for minimizing shapefile size without compromising geographical detail?

I work for a state government's fisheries service, and lately we've been digitizing a lot of our regulatory boundaries within the state's waters that we'd like to service out on web maps. ...
6
votes
1answer
295 views

Raster aggregation in ArcGIS Desktop?

I'd like to aggregate a raster from 1m to 6m in ArcGIS with a custom rule. For example, each cell value of aggregated raster = mean value of 5 highest cell values from 36 aggregated values. How do ...
16
votes
2answers
5k 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 ...
7
votes
2answers
633 views

Using ArcGIS to filter cells where 7 or 8 of neighbors are different

I have land cover data that I would like to clean using some generalization tools. Majority filter does almost exactly what I want, but is missing one key option. Majority filter allows you to change ...
6
votes
0answers
206 views

GeoServer pregeneralized layers not working as expected

I've set up GeoServer 2.1.4 and installed the feature-pregeneralized-2.1.4.jar plug in and processed my shape files into each of their separate folders with the generalized shapefiles and I've check ...
15
votes
2answers
1k 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. ...
6
votes
1answer
151 views

Finding Ring Smaller than a certain tolerance

In Simplifying a shapefile for world timezones http://efele.net/maps/tz/world/ all generalize/simplify algorithms fail on 5 countries/states, shown in this shape file ...
12
votes
3answers
13k views

How to smooth/generalize a polygon in qgis

Is it possible to smooth or generalize a polygon in qgis? Ìs there a plugin available like the generalizer-plugin for lines? I could convert my polygons to lines, smooth them and convert them back to ...
8
votes
2answers
2k views

Raster generalization - buffers in rasters, expand pixels?

Is it possible to create buffers for pixels of raster files? Actually I need to expand the pixels classified as 1 (in white in the figure) with a spatial range of 1 or 2 pixels, in order to perform ...
7
votes
4answers
1k views

How to aggregate detached polygons?

Is there any open-source library to aggregate detached polygons? I know that there is a tool in ArcInfo, but it is commercial.