GDAL Virtual Dataset (XML based)

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24 views

How to build .vrt of shapefiles?

I've a huge number of shapefiles and I would like to create a VRT as I do with gdalbuilvrt for raster. I find here https://github.com/dwtkns/gdal-cheat-sheet that it should be possible and the format ...
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1answer
29 views

Pulling a cvs file from a website into QGIS with the ability to automatically refresh.

I am attempting to pull a cvs file from a website that is updated daily. I would like to have a process that can automatically perform the process and save daily as a new layer. The cvs file is ...
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1answer
29 views

Overviews: to tiles or .vrt, or both?

When using vrt to mosaic on the fly large collections of images, is it better to add overviews (pyramids) to the individual rasters or to the final .vrt, or both? (Where "better" means finding the ...
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31 views

Cutting a shape from a VRT file with gdal warp

I have a couple of overlapping tif files which I want first to merge and then to clip a shape file from the result tif. The problem is that the tifs are pretty big and when the tiffs are overlapping ...
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87 views

gdal ReadAsArray returning NoneType

I'm trying to read in several rasters as array using gdal in a python script, but I keep getting NoneType returned and can't figure out why. The process is this: 1. Use gdalbuildvrt ...
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51 views

QGIS extremely slow to clip vrt on Mac

I've been using QGIS 2.6 (Brighton) happily for awhile but suddenly it became extremely slow during certain operations, after being reasonably fast in past use. I'm merging NAIP JP2 files to virtual ...
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1answer
67 views

How to use gdal_grid with VRT?

Hi folk's it seems to be that I'm to stupid to use gdal_grid. I' have file called dgm-10-epsg-32633.csv with equidistant samples 10x10m in this form. X,Y,Z 386700,6068670.000,.000 ...
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1answer
70 views

Reprojecting a CSV file using ogr2ogr?

I am trying to convert a CSV with fields in one projection system (EPSG:27700) to fields in another (EPSG:4326). I have made a VRT file called landfill.vrt, in the same directory as my CSV file, ...
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1answer
35 views

Efficiently working with converting vrt rasters to greyscale in QGIS?

I have large raster tile sets working well in QGIS (Ordnance Survey UK data). Sometimes I want to grey/fade these to make my data clearer to see. Attempting to access properties on QGIS for the VRT ...
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2answers
173 views

GDAL (or other open-source) equivalent of Arc's Point To Raster Tool

I'm trying to convert a python script that relies on arcpy into one that only relies on open source modules, but I'm having some trouble. The bulk of my processing lies in one Arc tool "Point to ...
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1answer
114 views

How to define layer style for KML layer within OGR Virtual Format?

I have the following OGR virtual format data source, which includes a few GeoJSON files and one KML file: <OGRVRTDataSource> <OGRVRTUnionLayer name="union"> ...
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39 views

OGR Virtual Format - How To Do Join

I have to kluge together a bunch of disparate data sources, and think the OGR Virtual Format may be an elegant solution. In looking at the documentation, I can't seem to find a way to join 2 layers ...
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1answer
255 views

Add band to GDAL VRT dataset and convert to TIFF

I'm trying to add a band to a TIFF dataset by converting it to a VRT format and using the AddBand() function, then convert it back to a TIFF to access the band and write the data. Here is an example ...
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1answer
75 views

Gdal_grid gives blank .tiff file after conversion

After using gdal_grid I get blank .tiff file. I use the following .vrt file : <OGRVRTDataSource> <OGRVRTLayer name="p"> <SrcDataSource>p.csv</SrcDataSource> ...
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606 views

Connecting ArcSDE to Quantum GIS for dummies?

I really have a need to be able to connect to and edit ArcSDE data in Quantum GIS. This question has been asked before and apparently is possible, but the instructions are just not specific enough ...
2
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1answer
247 views

gdal_grid with CSV file and VRT “No point geometry found on layer”

Given the following .vrt file which I manually created: <OGRVRTDataSource> <OGRVRTLayer name="DGM5_BE"> <SrcDataSource>DGM5_BE.txt</SrcDataSource> ...
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135 views

VRT vs KML superoverlay

We've got GB's of raster data that I want to make available as mosaics with overviews internally within my office. We have people using ArcGIS (although we are never all at the same version) and we ...
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70 views

How to prevent transparent borders (collars) of a tif wipe out overlapping regions of adjecent tif while using gdalbuildvrt

I have a set of Geotifs that have got transparent borders (collars) of irregular shapes & dimensions around them. First I created a VRT over this set of Geotifs through gdalbuildvrt. Then I ...
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1answer
111 views

Creating an OVF file for connecting Oracle and QGIS

I'm trying to create an OGR file that can be opened in QGIS that pulls in vector data from an Oracle Database. I've tried a few combinations of things but can't seem to get anything to work. I've few ...
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1answer
213 views

Set a RANGE of values as nodata in a .vrt?

Is it possible to set a range of values to nodata in a vrt file? How? I have some elevation models with incorrect values, down in the -15,000s. I could just clip the rasters along that edge, or apply ...
5
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1answer
661 views

ArcGIS Raster Mosaic Dataset and GDAL VRT, when to use?

ArcGIS Desktop has a the Raster Mosaic Dataset, QGIS and friends have Virtual Raster Tables. A skim of the documentation reveals much similarity. They both create or enable an alternate ...
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1answer
193 views

How to Set the Vertical Coordinate system when creating 3D Shapefile?

I have data of wells in CSV format, which I'm converting to a 3D shapefile, using ogr2ogr. The latitude and longitude are in WGS84, while the depth is from the WGS84 geoid. I have the OSGeo4W ...
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2answers
343 views

Python, GDAL, VRT: help wth code efficiency and processing time

I'm going to attempt to make this question as succinct as possible while still including relevant information, as I have trouble with being concise and am trying to avoid writing unnecessary stuff. ...
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2answers
181 views

gdal_grid has some problem with reading vrt file

I am using gdal_grid module(from gdal 1.10) and it has some problem with reading the vrt file. I checked this link but it does not work. gdal_grid problem reading vrt file The command is ...
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1answer
258 views

gdalbuildvrt error, when using in Python

I am new to python/GDAL and am running into perhaps a trivial issue. This may stem from the fact that I don't really understand how to use GDAL properly in python, or something careless, but even ...
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1answer
262 views

ogr2ogr csv conversion with latlon in one column

I have a csv with "lat\,lon" in a single column. I am trying to convert it with ogr2ogr to another format, and cannot figure out how to format the VRT file to accept this format. I cannot do ...
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1answer
195 views

How to get WGS84 lat lon bounds from a VRT file

I have vrt files generated using gdalbuildvrt that reference GeoTiffs referenced using the NZTM coordinate system. Is there an easy way to determine the bounds as WGS84 latitude longitude ...
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1answer
241 views

Writing array to vrt

I would like to write an array from a single band image to a 3 band vrt where each band has the ColorInterpretation() tag of red, green, blue respectively. My code below; from osgeo import gdal ...
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2answers
385 views

How practical is this workflow, tiling from a complex, multi-step GDAL VRT?

This is probably a cw-candidate, but here goes.. I've got 1002 ~100 MB (5000'x5000') .tif files in a state plane (transverse merc) projection comprising a county-wide, 1-ft aerial dataset. After two ...
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2answers
265 views

Some tiff not included on a vrt index

I have some tiff files and I'm trying to generate a vrt index with gdal tool, gdalbuildvrt. I run this command: gdalbuildvrt orto_index.vrt -srcnodata "0 0 0" -vrtnodata "0 0 0" *.tif and throws ...
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2answers
522 views

Having problems creating VRT in QGIS from png files

This is similar to a question asked by someone else, re OS tiles, however, there is a difference! I am a bit of a amateur in GIS and python, but if I take it slow I can usually just about work it out! ...
3
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1answer
205 views

How I can incorporate results of histogram stretching into georeferenced image?

I have one channel 8 bit raster and when I open it in QGIS with histogram stretching "on the fly" it looks fine. How I can recalculate original raster accordingly changed histogram?
6
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1answer
944 views

Python equivalent of gdalbuildvrt

Is there a way to perform the same task as the gdalbuildvrt utility using GDAL Python bindings? So far I have not found any way to do this other than creating a vrt of a single dataset and manually ...
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0answers
95 views

Size of output geotiff file not as in the .vrt file

I have the following vrt file (input.vrt) with GCPs in EPSG:3857 <VRTDataset rasterXSize="5409" rasterYSize="5408"> <Metadata /> <Metadata domain="IMAGE_STRUCTURE"> <MDI ...
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227 views

Issues with building a VRT. from OS map tiles in QGIS

I am trying to speed up rendering of OS raster map tiles in QGIS. The tiles are 1:10k Tiffs - about 130 of them. When I attempt to build the VRT it says complete, then it shows up an error ...
5
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1answer
3k views

GDAL VRT Format - do i understand the concept?

Okay, so im a little fed up with different raster-in-database solutions that I tried over the last 2 weeks which don't work currently (Postgis raster) or cant handle my volume of data (Rasterlite), so ...
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185 views

SAGA grid VRT, file how to apply a LUT?

I've created a heap of saga grid files for some hydro survey work. I'm looking at a way to read these into a mapguide raster/grid layer, I'm able to load up the grids using a vrt file, I can't figure ...