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

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36 views

How to smooth “internal” polygon borders

This is my first foray into GIS and GIS software. I am using ArcMap currently. I have a shapefile of the world divided into different ecological regions. I would like to reduce the file size by ...
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1answer
38 views

How are road polylines generalized?

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 ...
4
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2answers
106 views

Removing unnecessary vertices at places with no change of direction?

I am aware that this question has been asked here: How to remove unnecessary vertices. I want to focus a different point. How to remove unnecessary vertices without changing the shape at all. As you ...
2
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1answer
54 views

Generalizing (simplifying) polygon shapefile or feature class in ArcMap while preserving topology?

I came across How to generalize a polygon file and maintain topology in QGIS? which asks for a QGIS solution to my exact question. I'm trying to do this in ArcMap. I start with a polygon shapefile (...
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1answer
49 views

How to do a Loop with a condition in Model Builder?

Can I loop a set of actions in model builder while a specific features rows are 1 or more. Some background: I have a point layer where I've created a workflow that: first selects the row with the ...
3
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1answer
67 views

Loop and perform loop in order depending on attribute

I have a lot of points in one layer. All of which represent the same type of real world feature. I want to perform a delete identical within XY of each point but in a specific order. (by splitting ...
8
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3answers
160 views

Why are the holes in my polygons not generalized?

I have one polygon layer with many holes. I would like to generalize it. I used v.generalize of grass. With it, I used chaiken algorithm. But, only the borders of polygons were generalized, the holes ...
1
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1answer
44 views

How is width commonly defined for areal features?

Map generalization guidelines, for instance applicable to CORINE Land Cover or Polish BDOO databases state inclusion criteria for areal features like "area should be > 250 000 m^2 and width should be >...
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1answer
140 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 ...
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0answers
31 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
52 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
209 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 ...
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1answer
55 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
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1answer
67 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
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1answer
89 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 red....
0
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0answers
43 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
41 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
55 views

Combine two parallel lines to one with postgis [duplicate]

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 ...
1
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0answers
86 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
162 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 ...
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2answers
2k views

Removing 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 ...
3
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1answer
401 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
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1answer
116 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 ...
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1answer
92 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
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1answer
140 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 ...
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1answer
91 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
36 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
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1answer
514 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
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1answer
911 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
131 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?
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2answers
172 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
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1answer
120 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
298 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 ...
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1answer
84 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
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2answers
201 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
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1answer
479 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
706 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
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4answers
3k 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
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0answers
109 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
401 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
105 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
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1answer
407 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 ...
1
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0answers
52 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 ...
7
votes
6answers
996 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
255 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
174 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
213 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
3k 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
332 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 ...
17
votes
2answers
6k 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 ...