Tagged Questions

GDAL (Geospatial Data Abstraction Library) is an open source translator library & set of command-line utilities for processing raster spatial data formats. As a library, it presents a single abstract data model to the calling application for all supported formats. It also comes with a variety of ...

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0
votes
2answers
659 views

JP2 fails to open in QGIS and GDAL

I am trying to open a JP2 file in QGIS and it fails, and I'd appreciate any advice to try and track down the cause of the issue, be it with my system or with the file itself. The file is a HiRISE ...
1
vote
0answers
164 views

GDAL in Java fails on ReadRaster()

To summarize, trying to read a raster keeps giving me an UnsatisfiedLinkError that makes sense, but looking into the compiled GDAL jar, I don't know how to fix. gdal.AllRegister(); TheFile = ...
2
votes
1answer
129 views

gdal2tiles.py generating black tiles from .img file

I have a source HFA Erdas Imagine (.img) file which I'm trying to convert into tiles using gdal2tiles.py. I'm running: gdal2tiles.py -w google -g GOOGLEKEY input_file.img The HTML is generated ...
2
votes
0answers
131 views

Why is GDALPolygonize so much slower than ArcGIS Raster to Polygon?

I am attempting to polygonize a raster using GDALPolygonize() in a Python script. The script began polygonizing yesterday at 5pm and is still polygonizing now at 9:30 am. I have no clue how far ...
2
votes
0answers
31 views

Workflow to assign and reproject VRT [duplicate]

I have the following workflow. generate vrt from imagelist file(with paths to tifs/grids) check if coordinate transformation is required, if so convert to target SRS Create tile using gdal_retile ...
0
votes
1answer
476 views

GDAL RasterIO grabbing memory

I have written an application in c++ to read LiDAR files and convert to various rasters using GDAL; this worked very well on small scale tests (47 LAS files) however, when used on a live task the ...
1
vote
2answers
742 views

Python - GDAL : Polygon to point shape file

I want to read all the points in a polygon shape-file and use their coordinates to make a new point shape file. then find the min and max of the X coordinates. So here is the code I wrote for the ...
3
votes
0answers
78 views

Tabulate Area using GDAL and Numpy

How could I perform a Tabulate Area using GDAL and Numpy? I am trying to summarize how many pixels of each class in a Landcover raster are within each polygon of a Census Blocks shapefile. I've ...
1
vote
1answer
684 views

Delineate polygonal catchment areas from a raster using open-source GIS

I'm 90% sure this basic question has been asked before but looking through the other posts I simply do not see a useful answer. I need to calculate polygonal(vector) catchment areas from a raster ...
1
vote
1answer
94 views

Need assistance setting center coordinate with GDALWARP

I'm having some issues converting my project into an MBTiles format. I'm trying to use gdalwarp to convert my main file to geotiff format, but I can't seem to get the center coordinate to how it is ...
3
votes
0answers
174 views

Can GDAL Perform Vertical Transformations?

Can GDAL perform vertical transformations? If the answer is yes, please indicate which amongst these listed pages can explain how exactly to accomplish vertical transformations? If there is some ...
0
votes
2answers
212 views

GDAL and Python - Don't print GDAL Error messages

According to the GDAL Python Documentation, GDAL functions do not raise exceptions or errors but do print errors to the console via stdout and stderr. I have some code in my script that calls ...
3
votes
2answers
241 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 ...
3
votes
0answers
226 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
1
vote
1answer
59 views

Can I create a virtual mosaic using other virtual mosaics?

I am following this example - http://linfiniti.com/2009/09/image-mosaicking-with-gdal/ I have 6TB of aerial imagery in 6 folders 1TB each and each folder has many subdirectories including the ...
1
vote
1answer
159 views

Python/GDAL: Best way to read in raster for use in A* search algortihm

I want to create a least cost path program with Python and GDAL since I couldn't find any open source cost path additions for use in Python. As recommended here the best approach is to use A* ...
5
votes
2answers
3k views

How to add *.ecw files to QGIS 2.0 on Windows?

How do I add and view *.ecw raster images in Qgis 2.0 ?
1
vote
1answer
120 views

How to duplicate this QGIS workflow with gdal/GRASS? (reproject and crop a raster)?

I have a number of rasters (rgb images) that I want to re-project and crop. I have established a workflow for doing this in QGIS, but I'd like to do it using gdal modules, because the output is being ...
3
votes
2answers
527 views

How to set output resolution for gdalwarp to that of source file?

I have a large raster, which I want to re-project and crop for a new location that I'm creating in GRASS. I seem to have gotten the re-projection and cropping right with this call to gdalwarp: ...
1
vote
0answers
178 views

How to add new raster store and publish for ECW fromat in GeoServer 2.4-RC2?

I am using GeoServer 2.4 RC2 and Tomcat7 on windows xp OS. I have extracted the gdal-data.zip (2.4.0) and geoserver-2.4-SNAPSHOT-gdal-plugin into Tomcat 7.0\webapps\geoserver\WEB-INF\lib. Now ...
0
votes
1answer
211 views

Better way to handle HDF and GeoTIFF files

I am using GDAL and MODIS reprojection tool in my python project and want to know better way for math new indices of HDF data (MODIS data). Also I want to visualize them in web. Which format is more ...
2
votes
0answers
243 views

Buffering a Raster with GDAL and Numpy

I am using GDAL to convert a raster dataset into a numpy.array and then using numpy to buffer the data in the raster. For example, I need to know all the regions within 100ft of a school point ...
1
vote
1answer
371 views

Problem with GDAL_WMS QGIS connecting to an ArcGIS Server?

I've been working, trying to get QGIS (v2.0 32bit) to connect to an ArcGIS Server service using the GDAL_WMS xml file. This is the service I'm trying to connect to: ...
8
votes
2answers
720 views

Building FGDB support for GDAL 1.10 on Ubuntu

Because data.gc.ca is now distributing some of its data in FGDB format (example: Plant Hardiness Zones), I would like to be able to use it with gdal/QGIS. The compile/install is not going as planned, ...
2
votes
1answer
798 views

GDAL loads in Python, but not IPython (Linux)

I am trying my hardest to utilize the work of the good folks at the GeoDa center, but I cannot seem to get all of the components to load. GDAL, in particular, has been giving me some difficulty. The ...
1
vote
1answer
1k views

QGIS 2.0 Plugin error: Unable to load GdalTools plugin?

I just used the osgeo4w exe to install QGIS and all the other software included in the basic setup. When I open QGIS, I get the following error: Plugin error Unable to load GdalTools plugin. The ...
1
vote
1answer
108 views

Reading non-spatial Access tables with ogr2ogr

I am trying to read a whole Access database into Postgis using the ogr2ogr (Version 1.9.1) command. For some reason however, it only reads spatial tables and no non-spatial tables. All my attempts to ...
1
vote
0answers
89 views

How to join attributes by location with command line

I would like to joint the attributes of 2 shapefiles by location but with a command line (linux). This feature is easy in QGIS but it is VERY slow. Is there a way of doing this with ogr or pyqgis ? ...
0
votes
1answer
170 views

how to project a flat image to spherical mercator EPGS:900013 to use in a Image Layer in openlayers

I have a flat 400x400 pixels image which represents an area of 400x400 kilometers. I need to draw this image as an overlay on my OpenLayers mapping system. I use OpenStreetMap/Google Maps as base ...
2
votes
1answer
265 views

Problem with georeferencer in Qgis 2 64bit installation

I tried to use the georeferencer in the new Qgis 2 64 bits for windows. I tried with the standallone installer and with the OSgeo4w installer. The problem is when I load the raster that I want to ...
10
votes
6answers
835 views

How do I iterate through every cell in a continuous raster?

See this link for more details. The Problem: I want to loop through a continuous raster (one that has no attribute table), cell by cell, and get the value of the cell. I want to take those values ...
0
votes
2answers
697 views

How to extract subdataset from HDF raster?

I am trying to extract a subdataset from HDF raster. Later on, I intend to make operations such as mosaicking and extracting raster averages from the extracted subdataset. The following code is ...
14
votes
1answer
334 views

Why do people pronounce GDAL (Geospatial Data Abstraction Library) like goo-dal?

Ok, a bit of a silly question, but: I've heard people pronouncing the library GDAL (Geospatial Data Abstraction Library) like goooo-dal. My natural inclination was to pronounce it geeee-dal, as in ...
1
vote
1answer
132 views

GDAL reports no bands for a 12-band raster and no projection either

When opened in ArcGIS, the raster correctly unfolds 12 bands, but when I try to open it with GDAL through Python, it appears as a raster that has zero bands. Here is the code: import gdal from ...
1
vote
1answer
72 views

Which kind of grid format is this?

in a project I got some raster files with the following content (header and data are in one txt file): HOUR 17 MINUTES 30 YEAR 2012 MONTH 5 DAY 4 CITY Emilia;Bologna NROWS 99 NCOLS 156 ULXMAP ...
0
votes
1answer
108 views

gdallocationinfo is not recognized

I tried to run gdallocationinfo from my FWTools shell and got a message saying: "gdallocationinfo is not recognized as an internal or external command, operable program or batch file". So I checked ...
2
votes
1answer
391 views

Clip and copy files to same directory structure using OGR/GDAL with Python

We need to clip all our data (many TB) by a new boundary and save it while maintaining the same data structure. I want to use OGR/GDAL as the data is in shp/tab/kml/geoTif/ecw etc. I can find the ...
2
votes
2answers
230 views

MODIS calculations with non cloud contaminated pixels

I have 11 files showing 8day daytime LST temps in .tif format from MODIS. Is there any way to calculate the average 8day daytime temperature for march 2013 for example but using in the calculations ...
1
vote
2answers
174 views

will ogr get coordinates in geographic coordinate system or projected coordinate system when using getPoint(int,OGRPoint*)

Consider the code that I have written in the stackoverflow question How to extract vertexes of geometries in ESRI shapefiles using ogr library with c++, I have used the code to show shapefiles on an ...
0
votes
1answer
73 views

Where do I find the code for gd_calc.py?

I need to create a raster that is the average of a large set of other rasters (many thousands). I've learned from another question that the script gd_calc.py can do a limited version of this, limited ...
0
votes
2answers
165 views

How to average a set of n rasters using gdal or other GRASS module? [duplicate]

I need to average a set of n rasters using gdal or some other GRASS module. What command exists for this purpose?
1
vote
1answer
308 views

How to convert 4-channel PNG files to grayscale geoTIFFs?

I suspect that there exists a gdal tool (gdal_translate?) that will convert a 4-channel PNG (+ world file) to a 1-channel (gray-scale) geoTIFF. From the gdal_translate man page, it appears simple to ...
2
votes
1answer
110 views

GDAL local files VS ftp files

I can successfully get raster information when the raster file is located on my local file system: import gdal from gdalconst import * filename= "MOD11A1.A2012193.h11v11.005.2012196013534.hdf" ...
-3
votes
1answer
78 views

How can I use ogrinfo to reach information anout a .shp?

How can I use ogrinfo? where should I write it? In the visual studio's command prompt or somewhere else? Can you make some examples? when I use ogrinfo in the windows or visual studio's command ...
2
votes
1answer
66 views

What does the predictor switch do while compressing geoTIFFs in GDAL

I am merging several geoTIFFs into one and am using the -co COMPRESS=DEFLATE create option for geoTIFFs. An additional switch is the predictor switch. What does it do? The GDAL website is not clear ...
1
vote
0answers
79 views

Contours generated from merged TIFs huge - much bigger than individually

I'm generating contours from four 5x5 degree SRTM DEMs in southeastern Australia. I'm using gdalwarp to reproject the DEM, then gdal_contour to generate contours. First, I generated contours for each ...
2
votes
2answers
323 views

How do I know the vertical/horizontal units of my DEM? I'm creating a slope using gdaldem

I'm using gdaldem to create a slope map. I can apply a scale. The default is 1. The notes say: Ratio of vertical units to horizontal. If horizontal unit of source DEM is degrees (e.g WGS84 ...
2
votes
0answers
94 views

Displaying DEM raster in QGIS

Using Raster>Analysis>DEM to display hillshade produces the message "gdaldem.exe had stopped working" so I asked the community. I'm new to QGIS, and I now realise after a little experimentation that I ...
0
votes
0answers
211 views

How to read vector datasets using GDAL library

Up to now, I have used GDAL in order to read raster information and geotiffs and show them with the help of OpenGL. Now I have a vector dataset, and by that, I mean I have the files with types: DBF ...
1
vote
0answers
480 views

How to generate JPEG tiles using gdal2tiles.py

I am using gdal2tiles.py to generate tiles and packing it into MBTiles using mb-util. gdal2tiles by default generates PNG tiles. When I convert PNG tiles to JPEG large black area around tiles are left ...