32 votes

Extracting raster values at points using Open Source GIS?

I was having problems with the QGIS and SAGA GUI tools mentioned in this thread (Raster values to points was failing for some reason and throwing unhelpful errors and the GRASS v.sample created a ...
Ian's user avatar
  • 485
24 votes

Splitting raster into smaller chunks using GDAL?

There's a bundled python script specifically for retiling rasters, gdal_retile: gdal_retile.py [-v] [-co NAME=VALUE]* [-of out_format] [-ps pixelWidth pixelHeight] [-overlap ...
mikewatt's user avatar
  • 5,083
14 votes

Alternatives to Shapefiles as open-source, cross platform dataset types

A new format that has come about recently is the Geopackage. This specification is built on top of the SQLite database, so it has the same single-file basis, but with the added benefit of being an ...
Get Spatial's user avatar
  • 13.3k
10 votes

Layman friendly method to create a shapefile

QGIS is a free, open source GIS. It can be downloaded at https://qgis.org/en/site/forusers/download.html. The program comes with some tutorials, including how to create a shapefile. This is the link ...
Kingfisher's user avatar
  • 2,314
8 votes
Accepted

Standard Deviational Ellipse with Open Source Python (GDAL/OGR etc)

The Standard Deviational Ellipse from ArcGIS is not the only solution. In the geospatial world, there are two major algorithms (Yuill and CrimeStat III) and many intermediate solutions (QGIS: des ...
gene's user avatar
  • 54.9k
7 votes

Extracting raster values at points using Open Source GIS?

Try using QGIS 3.2.2 and SAGA (installed by default in QGIS): "Raster Values to Points" function will do everything for you: It takes a image file and converts it into a Point-vector shape taking the ...
Fernando MM's user avatar
7 votes

GDAL/OGR (Python) GetGeomType() method returns integer, what is the matching geom type?

If you need to determine the type in code, use the ogr.wkb* constants as per @iant's answer. Alternatively, if you just want to print out the type, you can use the ogr.GeometryTypeToName function. ...
user2856's user avatar
  • 65.8k
6 votes

Splitting raster into smaller chunks using GDAL?

You can use r.tile of GRASS GIS. r.tile generates a separate raster map for each tile with numbered map names based on the user defined prefix. Width of tiles (columns) and height of tiles (rows) can ...
markusN's user avatar
  • 13k
6 votes

Splitting raster into smaller chunks using GDAL?

For @Aaron who asked: I am hoping to find a gdalwarp version of @wwnick's answer that utilizes the -multi option for enhanced multicore and multithreaded operations Slight Disclaimer This uses ...
RoperMaps's user avatar
  • 2,166
6 votes

Free implementation of Polynomial Approximation with Exponential Kernel (PAEK) algorithm

I came across a thread Smoothing a 2-D figure. The answers make reference to this paper Chaikin's algorithm for curves For a given polygon with vertices as P0, P1, ...P(N-1), the corner cutting ...
whyzar's user avatar
  • 12.1k
6 votes
Accepted

What is the correct format for APA referencing maps produced in QGIS, including data layers?

There are a few options I've come across and would use similarly: According to the Purdue Online Writing Lab (OWL) Reference List: Electronic Sources (Web Publications) they provide citation methods ...
whyzar's user avatar
  • 12.1k
6 votes

Options for visualizing LiDAR data on (Mac) OS X?

Some options: Cloud Compare: Open-source visualization software. A third-party pre-built executable for Mac is available from https://asmaloney.com/software/, or you can build from source. Includes ...
Pete Gadomski's user avatar
6 votes
Accepted

Getting lat&lon extent of country by its name using Python

Function to get bounding box or center coordinate in list given different options for country name: def get_boundingbox_country(country, output_as='boundingbox'): """ get the bounding box of ...
Mattijn's user avatar
  • 966
6 votes

Seeking open source ArcGIS REST API compatible server?

The answer is 'yes' and 'no'. Let me explain. As Bill mentioned, there are plenty of implementations of various OGC standards WFS, WMS, TMS, etc. (see Geoserver, Mapserver, Tilestache, etc). However,...
Ragi Yaser Burhum's user avatar
6 votes
Accepted

GDAL/OGR (Python) GetGeomType() method returns integer, what is the matching geom type?

You will find the output variants of WKB types supported by GDAL here: OGC 06-103r4 "OpenGIS® Implementation Standard for Geographic information - Simple feature access - Part 1: Common architecture",...
mgri's user avatar
  • 16.2k
6 votes
Accepted

Accessing raw data from LAZ file in Python with Open Source software?

A convenient way to get point cloud data to Python is to use the PDAL Python extension. PDAL uses the concept of pipelines (much like a GDAL VRT for point clouds instead of rasters) to allow users ...
Howard Butler's user avatar
6 votes

Seeking (Open Source) Mobile GIS app for survey?

Have a look at the Mergin Maps Input app from Lutra Consulting: https://merginmaps.com It synchronises well with your QGIS project and has a cloud service for synchronisation. Here's a tutorial: ...
Hansakwast's user avatar
5 votes

Creating drive time polygons using Open Source tools?

You might want to check out the open Route360┬░ JavaScript API, which works with both Leaflet and Google maps. It returns travel time polygons for the following travel modes: walk, bike, car, transit. ...
5 votes
Accepted

Image segmentation in open-source software

For Python, there are very few option for free source RS based image segmentation. I'll suggest two, Orfeo Toolbox: Probably the best free alternative of eCognition. It has quite a few segmentation ...
blu_sr's user avatar
  • 785
5 votes
Accepted

How to drape image on surface using open source software?

You can use Qgis2threejs plugin in QGIS to view an image in 3D. It has great options and potential capabilities that you can see in the plugin's documentation. Then plugin can be downloaded from QGIS ...
ahmadhanb's user avatar
  • 40.9k
5 votes
Accepted

How could we get presentation of FOSS4Geurope 2017?

The conference website provides a link to a repository with the presentations. Unfortunately it's hidden behind a link saying "OSGeo Repo for FOSS4G Europe 2017 Conference" which is easy to miss. ...
pLumo's user avatar
  • 6,489
5 votes
Accepted

Open source approach to classifying and removing LiDAR points from overlapping scans?

There are a couple of options. Depending on the area of MN where you're processing, the overlap areas of the data are classified, and you can use a PDAL filters.range to cull them out: pdal translate ...
Howard Butler's user avatar
5 votes
Accepted

Open source desktop GIS for high school curriculum?

If you are interested in a desktop GIS application similar to ArcGIS but open source, QGIS is definitely the way to go. There are even two books specifically for use in class rooms at https://...
underdark's user avatar
  • 84.1k
5 votes
Accepted

Rasterizing ungridded XYZ (LiDAR) files?

For simplicity (because it was not mentioned in question) I am assuming the XYZ files are ready to be processed (i.e., no classification or filtering is needed) and that the content is suitable for ...
Andre Silva's user avatar
  • 10.3k
5 votes
Accepted

Compress Large size of satellite image by Open Source GIS software

When in doubt follow Paul Ramsey's GeoTiff compression for dummies strategy. gdal_translate \ -co COMPRESS=JPEG \ -co PHOTOMETRIC=YCBCR \ -co TILED=YES \ 5255C.tif 5255C_JPEG_YCBCR.tif and ...
Ian Turton's user avatar
  • 81.5k
4 votes

Is there any open source library for reading OCAD files?

If you want to migrate from OCAD to some free & open-source software then, I highly recommend you useOpenOrienteering Mapper (OOMapper for short) - cartographic desktop publishing software for ...
User1's user avatar
  • 41
4 votes

Alternatives to Shapefiles as open-source, cross platform dataset types

Agree with Lennert, choose the right format for the job. However I have found Spatialite to be a pretty versatile format. You have the single file giving you have the flexibility in storing and ...
Liam G's user avatar
  • 2,156
4 votes

Alternatives to Shapefiles as open-source, cross platform dataset types

There are a lot of different formats and the best depends on your data set you have, the tools you use and the things you want to do with it. Some of the ones I use: File Geodatabase & ...
Lennert De Feyter's user avatar
4 votes
Accepted

How to rectify polygon shapes in QGIS?

There is a QGIS Tool called Oriented minimum bounding box. You can find it under Processing > QGIS geoalgorithms > Vector general tools. I'm using QGIS 2.18. Maybe this comes close to what you ...
Stefan's user avatar
  • 4,414
4 votes

Open Source Remote Sensing vs eCognition, ERDAS etc Is it worth it?

From own experience, I can warmly recommend having a look at GRASS GIS 7. It can handle a huge amount of data and comes with a lot of RS tools out of the box (from image enhancement, via segmentation ...
Stefan B.'s user avatar
  • 286

Only top scored, non community-wiki answers of a minimum length are eligible