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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24
votes
3answers
6k views

What is Lanczos resampling useful for in a spatial context?

GDAL includes a resampling method beyond the normal mix of nearest neighbor, bilinear, cubic and splines: "Lanczos windowed sinc resampling". I understand that its a convolution filter, but unlike ...
13
votes
2answers
3k views

How to smooth/interpolate a raster in python using GDAL?

This is my first post so please feel free to critique where necessary. Background: I am developing in Python and using GDAL from OSGEO to manipulate and interact with rasters and shapefiles. ...
14
votes
11answers
13k views

Python GDAL package missing header file when installing via pip

I asked this question on Stack Overflow before I realised this site existed. As this site it more appropriate, I'll ask it here too. I'm trying to install gdal from pip pip install gdal inside a ...
13
votes
3answers
8k views

How to georeference a web mercator tile correctly using gdal?

As an example I will take the following tile http://a.tile.openstreetmap.org/3/4/2.png and save it as "4_2.png". The WGS84 coordinates of this tile can be calculated or read there by clicking the ...
10
votes
3answers
6k views

How to fully load a raster into a numpy array?

I have been trying to check my filters on DEM raster for pattern recognition and it is always resulting in missing last rows and columns(like..20). I have tried with PIL library, image load. Then with ...
9
votes
2answers
3k views

How to get raster corner coordinates using Python GDAL bindings?

Is there a way to get the corner coordinates (in degrees lat/long) from a raster file using gdal's Python bindings? A few searches online have convinced me that there is not, so I have developed a ...
11
votes
2answers
3k views

How to split shapefile per feature in Python using GDAL?

is it possible to split a shapefile per feature in python? (best would be a solution where i can temporarily save the resulting vector objects to the memory instead to disk). The reason: I want to ...
13
votes
2answers
5k views

API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty ...
11
votes
5answers
4k views

installing GEOS, PROJ, GDAL/OGR into a python virtualenv on Mac OS X

I am trying to setup an isolated python virtualenv to work on GIS projects on my Mac OS X. Sounds like I will need to install the GEOS, PROJ, GDAL/OGR from the kyngchaos site here ...
9
votes
1answer
1k views

Importing GDAL from Python window of ArcGIS for Desktop?

I am trying to run some Python code using the Python window in ArcGIS 10.1 that uses both the arcpy and gdal modules. However, when I try and import the gdal module I get an error: ImportError: No ...
6
votes
1answer
5k views

How to import a raster into PostGIS?

I'm trying to follow the instructions here to load a raster into a PostGIS database: python raster2pgsql.py -s 4269 -I -r *.tif -F myschema.demelevation -o elev.sql I understand that I replace * ...
3
votes
2answers
401 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 ...
6
votes
1answer
974 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 ...
5
votes
2answers
2k views

GDAL Python bindings not picking up OGR PostgreSQL driver

I have a windows server (Microsoft Windows Server 2003) with: Python 2.7, PostgreSQL 9.04-1, GDAL 1.8.1 (installed from the windows installer (gdal-18-1500-core.msi) hosted at ...
2
votes
1answer
463 views

PostGIS Raster in MapServer

I'm having trouble getting a PostGIS raster to load and display in MapServer. I'm not sure, but suspect it's a version problem. My mapfile layer and the error message are shown below. LAYER ...
2
votes
2answers
620 views

How to re-project the EASE (Equal Area Scalable Earth) grid with a ~25 km cylindrical projection to WGS84 0.25 degree?

I have nc files. from the metadata ,the projection is cylindrical and the resolution is 25 km: indrical NC_GLOBAL#ease_resolution=25 ...
10
votes
3answers
2k views

getting dxf files out of PostgreSQL

I've successfully loaded a bunch of shapefiles into a PostGIS database. I would like to be able to retrieve specific geometry and layers as dxf files based on SQL queries. I'm using PostGIS, GDAL, ...
8
votes
4answers
3k views

Open source software to merge large shape files

Some background: I have 2 polygon shape files with approximately 500,000 records each. The two files are identical in terms of field structure. Using ArcGIS 10.0 I can'nt merge these two files using ...
7
votes
3answers
8k views

How can I get the proj4 string or EPSG code from a shapefile .prj file? [duplicate]

I have to work with a shapefile defined in an unusual projection, which my GIS software does not know about. How can I get the proj4 definition or the EPSG code for the projection?
6
votes
3answers
971 views

How to convert factfinder2.census.gov map data to KML?

I've downloaded a map from http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=DEC_10_SF1_P1 (limited to San Francisco census tracts), and I'd like to convert it to KML ...
4
votes
1answer
647 views

How to apply “Band” settings using gdal Python bindings?

I am trying to replicate the gdal_translate command, but using pure Python: gdal_translate infile.tif outfile.tif -co COMPRESS=JPEG -co PHOTOMETRIC=YCBCR -co TFW=YES -b 1 -b 2 -b 3 I have ...
4
votes
2answers
2k views

how to for loop a folder to batch clip rasters by polygon using python and QGIS

I am using python and QGIS 2.0. I am trying to clip rasters in a folder by one polygon feature. It's the first time for me using (let's say) "PyQGIS", I was used to arcpy before. Anyway, I don't get ...
4
votes
2answers
694 views

What's the best projection for rasterization of random latitude and longitude data in the northern Atlantic?

I have a dataset in the WGS84 geographic coordinate system that I would like to interpolate along a grid using Python. It appears gdal_grid is not available through the Python bindings, so I plan to ...
4
votes
2answers
4k views

How to install stable GDAL on Ubuntu 11.10?

I am trying to install the stable ubuntu package from here https://launchpad.net/~ubuntugis/+archive/ppa/+packages on my ubuntu 11.10 server I have added the ubuntugis stable repository to server's ...
3
votes
1answer
583 views

How to run OSgo4W shell script on Windows?

I have a lot of DEMs that I want to use to create hillshades, slopes and color relief from and would like to automate the processes using a shell script within OSgeo4W shell. Here is the code I used ...
3
votes
1answer
536 views

Get the geotransform in Mercator given a pixel size away from the origin

I have a radar image with the following information: The projection is Mercator (Mercator_1SP in GDAL) The projection origin is 0º lat 0º lon At a given geographic coordinates (e.g. lon=10º ...
2
votes
1answer
216 views

gdalwarp won't export AAIGrid

I'm trying to use gdalwarp to reproject an ascii grid file. According to http://www.gdal.org/formats_list.html this shouldn't be a problem and indeed I can happily use gdal_translate to create grd ...
2
votes
1answer
296 views

How to remove strange gdaldem hillshade artifacts?

I've downloaded 9 chunks of 1 arc-second NED in IMG format from the National Map. I'm trying to create a hillshade from them. I'm using: GDAL 1.10.0, released 2013/04/24 First, I combine them and ...
2
votes
1answer
433 views

How can I dynamically trim the informational border off of FAA sectional raster charts?

I'm trying to write a script that can automatically use GDAL to crop the informational border from the FAA's published sectional charts (GeoTIFF) found here: I know that I can use gdal_translate ...
2
votes
1answer
281 views

Gdal_polygonize: How to filter pixels above a given value (elevation)?

Given a topographic GIS raster of one country: Given an elevation threshold n = 50 (meters) How to polygonize pixels when z >= n ? gdal_polygonize.py is not clear on this point. It states This ...
2
votes
1answer
810 views

merge raster images: error message procedure not found

I am using QGIS 1.8.0. Whenever I try to merge raster images I get the following error message: Traceback (most recent call last): File "C:\PROGRA~1\Quantum GIS Lisboa\bin\gdal_merge.py", line 36, ...
0
votes
1answer
157 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 ...
6
votes
3answers
2k views

How do I extract a raster's extent in python?

I am looking for an easy way to extract a raster's extent in python. Currently, I am using gdalinfo and then parsing out the corner coordinates. The problem with this approach is that gdalinfo is ...
5
votes
2answers
191 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 ...
4
votes
2answers
4k views

How to convert a .tif with .tfw to a GeoTiff?

I have a tif image file, and a .tfw world file (created from OSM data with Mapertive). How can I (using linux command line) convert that to a GeoTIFF file? (i.e. I want to have one file, not 2). I'm ...
4
votes
0answers
891 views

Reprojecting WGS 1984 Web Mercator (EPSG:3857) in Python with GDAL

I am reprojecting rasters in python using GDAL. I need to project several tiffs from geographic WGS 84 coordinates to WGS 1984 Web Mercator (Auxiliary Sphere), in order to use them later in Openlayers ...
4
votes
2answers
1k views

Issue Trying to create Zonal Statistics using Gdal and Python.

I am trying to create zonal statistics using Python and Gdal. I have a polygon shapefile and a raster file, and in order to do so, I am using a piece of code I found in StackExchange. The raster and ...
4
votes
1answer
458 views

gdal_translate- why jpg compressed tif is 2 times greater than jpg file?

Using the following two commands yields completely different size files: gdal_translate test.tif -of GTiff -co "COMPRESS=JPEG" -co "JPEG_QUALITY=100" output.tif and gdal_translate test.tif -of JPEG ...
4
votes
3answers
3k views

GDAL_translate: converting ESRI GRID to Geotiff in batch

The Challenge: To batch convert 1000 rasters in ESRI Grid binary to Geotiff using either using a batch file or Python 2.7 without ArcGIS/Arcpy module. The Tools: Win7Pro, GDAL 1.9.2 (via OSGeo4W), ...
4
votes
1answer
888 views

How to sum or even perform more complex mathematical operations (multiply, add a constant, …) two GDAL grids?

I have two grids with same cell size, same starting position (top left) and same grid size. I want to sum the grids and create a sum grid as an result: e.g. grid A + grid B = grid C How can I ...
4
votes
3answers
3k views

How to generate a shapefile containing an UTM grid (graticule)?

I'm looking for a shapefile containing an 1000m or 2000m UTM grid ("graticule"). All I was about to find on the web is a 10000m UTM grid (here: http://en.giswiki.net/wiki/UTM) and I am aware that a ...
4
votes
2answers
1k views

Translating grid to USGS .dem in C# via GDAL

I am attempting to translate ArcInfo binary grids to USGS DEM format (.dem). I have installed the GDAL .NET bindings thru this build installer. I can get to GDAL in my C# add-in I am working on. ...
3
votes
1answer
162 views

Reprojecting a raster image using gdalwarp

I am trying to reproject an ECW Orthophoto from 25830 to 23030 srid. I tried the following but I am getting an error: C:\Program Files (x86)\FWTools2.4.7>gdalwarp -s_srs 25830 -t_srs 23030 ...
3
votes
2answers
147 views

gdalwarp leaves horizontal artifacts regridding from EASE-Grid (laea) to Polarstero (stere)

I'm trying to understand how to use gdalwarp to warp an image. I believe I'm doing the basics correctly, but I might be missing some gdalwarp options? Any help would be greatly appreciated. The ...
3
votes
1answer
1k views

Re-project raster image from Mercator to Equirectangular

I have a raster image of the world map in Mercator projection, square 1:1 format. I want transform the image into an Equirectangular projection accurately. I assumed from my research that GDAL would ...
3
votes
2answers
517 views

GDAL TMS (WMS) mini driver

I've a problem with GDALs TMS mini driver. I've created an xml file, which i can open in qgis. I am using local tiles on my computer which i prerendered with mapnik, the map covers entire country of ...
3
votes
1answer
902 views

Serving 4 band GeoTIFF in GeoServer 2.1.4

I have an uncompressed GeoTIFF file (figure 1) with the following band information: Image Structure Metadata: INTERLEAVE=PIXEL Band 1 Block=5000x1 Type=Byte, ColorInterp=Red Band 2 Block=5000x1 ...
3
votes
2answers
857 views

How can I merge geotiffs with a vrt file?

I have heard that I can use a vrt file to merge mulitple geotiffs into one? what is the syntax? gdal_tranlsate -of VRT file1.tif file2.tif file2.tif Something like this?
3
votes
2answers
2k views

Error installing GDAL 1.9.0 python package

I'm trying to install the GDAL python package in a python 2.7.1 environment on RHEL 5. I am using the command 'pip install GDAL'. I have no problem installing other packages like numpy, etc. in this ...
3
votes
2answers
780 views

Overlaying GPX data on rasters in QGIS

I have a series of raster map images that I would like to use in QGIS and overlay some simple GPX routes over the top to produce a custom map image. This is all quite new to me so please bare with ...