GDAL Virtual Dataset (XML based)

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2
votes
2answers
10 views

GDAL grid produces NoData

I have a series of text files that represent X,Y,Z elevation data. I'm trying to use the GDAL grid command line tool to convert these text files to raster GeoTIFs. My files are space delimited and so ...
15
votes
1answer
1k 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 ...
3
votes
1answer
67 views

Hillshades created from QGIS Virtual Raster Tables sometimes have unwanted artifacts

Using QGIS 2.14.3 I tested Virtual Raster Table technology for the first time using two TIF DEMS (NED 1/3 arc-second, projected to EPSG:3338, single band, 32-bit floating point, ~ 5-meter resolution). ...
0
votes
1answer
14 views

Get GDAL to convert all four bands to a VRT from a NITF?

So I have a series of four band NITF images (RGB + Near Infrared). I am currently storing them in a VRT with gdal_translate. Unfortunately, gdal_translate keeps interperting the fourth band as an ...
0
votes
1answer
47 views

Understanding GDAL ERROR 1: Too many points… failed to transform?

How can one trace the source of the following error when using gdalwarp? (I'm very new to GIS, GDAL and python!) Warning 1: Unable to compute source region for output window 0,0,5789,4748, ...
4
votes
0answers
77 views

OS terrain 50: .vrt from zip files

I tried to follow what was suggested in How to use OS Terrain 50 in QGIS, but I got the following problem: in spite of being generally able to generate .vrt files using gdalbuildvrt from unzipped ....
2
votes
0answers
164 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 ...
1
vote
0answers
17 views

Raster Imagery Performance

I'm currently building a project that will involve using raster imagery in the field on a Windows tablet with QGIS/Intramaps Roam and haven't been able to get a satisfactory understanding of a few ...
1
vote
0answers
34 views

How to dynamically change the draw-order of geotiff rasters in QGIS?

In ArcGIS it is possible, via raster mosaics, to choose the raster order depending on various methods. One such method is the center method. The raster that is closest to the coordinate of the center ...
1
vote
0answers
150 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 ...
1
vote
0answers
114 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 ...
1
vote
0answers
316 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 message:...
0
votes
0answers
15 views

mapserver vrt et mapfile : file not found or unsupported format

I try to create a mapfile with data in a csv file. I have failed to draw the layer with a Virtual Format and a OGR connectiontype directly in the mapfile. So I have decided to store the connection in ...
0
votes
0answers
7 views

I can't display a vrt layer with mapserver 6

I have created a connection type OGRVRT in a mapfile to display a csv file. It doesn't work : it says that the memory can't be read. I can't find the reason why. Here is the mapfile : LAYER ...
0
votes
0answers
23 views

ogrinfo : couldn't fetch requested layer

Apache version 2.2.22 PHP version 5.4.3 MapServer 6.0.3 CGI and MapScript (CSharp, Java, PHP, Python) GDAL 1.9.1 mapserver utilities gdal/ogr utilities windows I have created an odbc connexion ...
0
votes
0answers
24 views

gdalwarp not clipping VRT to correct extent

I'm trying to clip a projected .vrt raster to an extent expressed in GCS coordinates and it's not doing what I would expect. Here is my command: gdalwarp -te -133.08813624 56.69042536 -132.69405069 ...
0
votes
0answers
36 views

Zoom to a subfile/ calc the extent of a section of a VRT in QGIS

I want to write a plugin in QGIS, which first creates a VRT from TIFs in a directory with gdalbuildvrt . Later my plugin will get a parameter, a name of a subfile of this vrt. Now I wonder how to ...
0
votes
0answers
26 views

Mapnik tiling speed help

I am working with a large series of jp2 files and need to mosaic and web map tile them. I would like to go form zoom 1-20. I am using mapnik to tile my images. Using gdalbuildvrt I was able to build ...
0
votes
0answers
63 views

GDAL error in QGIS application displaying VRT files

I am working with a standalone app build with QGIS 2.8.1 on a CentOs7 machine. I got a new DTED data set which raises errors "somewhere" in the app. The app doesn't read the .dt? files directly, but ...
0
votes
0answers
168 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 ...
0
votes
0answers
135 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 ...
0
votes
0answers
253 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 (http://www.gdal....
0
votes
0answers
209 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 ...
0
votes
0answers
208 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 ...