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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2
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1answer
423 views

How to manage null values in QGIS

I made a merge of several AsterGdem blocks near Egypt and Israel. I have portions of the Dead and Mediterranean Seas. Since near Galilea elevations are below sea level this makes the following problem ...
0
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0answers
135 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 ...
1
vote
2answers
2k views

Clean way to install gdaltools plugin for QGIS on OSX

I have qgis 1.8.0 on osx mountain lion and am installing the gdaltools 1.2.29. I have run into a problem that a number of people are seeing. The plugin cannot find my gdal python (see below). ...
7
votes
1answer
2k views

GDAL RasterizeLayer Doesn't Burn All Polygons to Raster

I am trying to burn a shapefile to a raster using GDAL's RasterizeLayer. I pre-create an area of interest raster from a different shapefile, given a specific pixel size. This AOI then serves as a base ...
8
votes
1answer
959 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 ...
0
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2answers
227 views

Why does gdalbuildvrt not allow these things?

I don't know why does gdalbuildvrt not allow: Unreferenced images Rotated images South up images Could someone throw some light? Many thanks in advance
2
votes
1answer
79 views

What should I expect in this case?

If while I'm executing gdalinfo against a raster layer I get a positive value for pixel size Y, what of these scenarios is possible? The raster's map coordinate system sets the origin of the data in ...
4
votes
1answer
404 views

raster algebra in python with rasters of different extents

I am trying to find out how to use GDAL & numpy modules to average a set of rasters....which are Sigma0 values from satellite passes at different times within a year. Each raster has been ...
3
votes
1answer
242 views

Projecting GCP points into translated file

I have file A.png and file B.png. I translate file A.png so i could translate it into B.png (creating multilayer file). Is there any easy way to get new GCP points coordinates so i could combine those ...
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0answers
220 views

Homebrew GDAL installation ECW or MrSID

I have experimented with installing gdal 1.9.1 via homebrew. It works wonderfully. Unfortunately, their is no real JP2000 support. I realize that JP2000 is supported by OpenJp2000, but that ...
3
votes
0answers
359 views

How to save table from PostgreSQL to MapInfo File?

I have two tables: 1 with geometry in WGS 2 with geometry in Local System I tried this: ogr2ogr -f "MapInfo File" output2.tab PG:"host=localhost user=postgres password=123456 dbname=postgis" -sql ...
2
votes
2answers
397 views

Using osgeo modules in ArcGIS10.1 and QGIS 1.8 python shells

This is related to an old question of mine - Issues with osgeo - qgis.core and arcpy modules Now in new versions of all the software QGIS Lisboa (1.8), ArcGIS 10.1 and pyScripter 2.5.3. They all use ...
0
votes
0answers
484 views

How to add ECW support to GDAL bundled with PostGIS Windows

I'm currently trying the new raster functionalities of PostGIS 2.0 and I successfully imported some GeoTIFF file into PostGIS (although it only find one band so it's all black and white for some ...
0
votes
1answer
386 views

Vector boundary generation -similar to Image Boundary

I want to automate the creation of boundary polygons from vector files. This is not footprint or extent creation (I already have scripts to do this). I want to create a tool similar to the QGIS, Image ...
1
vote
1answer
397 views

GDAL: C++ API to Convert Text file of Coordinate points to Raster Pixel line?

I am using GDAL to "Grow" areas form starting seed points. I have a text file listng the coordinates of my seed locations. The X,Y coordinates are in the coordinate system of a raster image. I want ...
1
vote
0answers
162 views

gdallocationinfo from C++?

I need a C++ API to convert x,y Image Coordinates in their native projection to output image pixel,line coordnates. I see the gdallocationinfo documentation, but no API for it. Where in online GDAL ...
3
votes
1answer
827 views

How do I split polygons that cross the dateline?

I have a dataset of country borders which I obtained from: http://thematicmapping.org/downloads/world_borders.php/ I have that dataset in both shp and SQL, but I'll put out there that I don't feel ...
1
vote
2answers
870 views

GDAL does ECW but QGIS (Linux !!) does not load ECW file

Followed instructions from various posts (each one with slight variations on the theme) and most of the time have no trouble getting the installed GDAL to accept ECW files. However, QGIS stubbornly ...
3
votes
1answer
322 views

How to stop writeOGR from abbreviating Field Names when using “ESRI Shapefile” driver

I'm currently using the following script to add some attribute data from a table to lots of individual shapefiles: library(rgdal) specieslist <- read.csv("SpeciesList1.txt", header=F) attdata ...
1
vote
3answers
467 views

Getting Field value for a given coordinate out of ESRI Shapefile using GDAL/OGR

I have a bunch of ESRI shapefiles that contain Land Cover data across Canada (provided by Geobase). I need to query the files and obtain the value of a certain field (called COVTYPE) in a given ...
6
votes
3answers
1k views

How to smooth / “reinterpolate” a raster with GDAL?

Short: I want to change the resolution of a raster and smooth the gray ramp like shown in the images bellow. The preference is to use GDAL, PIL or Numpy. Description: I'm kriging points into rasters ...
7
votes
2answers
457 views

How to catch PostgreSQL/PostGIS errors in GDAL/OGR Python bindings?

Is it possible to catch PostgreSQL output error messages in OGR after a query has failed? For example conn.ExecuteSQL('SELECT * FROM non_existing_table;') In Postgres this returns an error ...
8
votes
1answer
360 views

Is there a way to properly have GDAL raise exceptions in Python?

I am working with GDAL in Python and have wanted to get GDAL to raise exceptions so that I can do something useful with them. For instance if a file cannot be opened with gdal.Open() I would like to ...
0
votes
1answer
547 views

Qgis install can't find Gdal framework (Mac OS X 10.7)

After having installed Mac OS X 10.7 I can't install Quantum Gis as it maintains that I have not installe the GDAL Framework, which I have done (several times). Have anyone experienced the same ...
3
votes
1answer
570 views

Merging raster data with different resolutions

I need to merge different raster datasets which have one layer and contain discrete values to a layer stack. The resolutions of the data can have any value so not only multiples of the resolutions ...
2
votes
1answer
888 views

SID and/or ECW support on QGIS for Linux

Running QGIS on Ubuntu 11.04 and QGIS for Android on Galaxy Tab 10.1 (which is an awesome project by the way) NEED to figure out a way to get SID and/or ECW files loaded. Saw some posts about ...
1
vote
3answers
355 views

How can I translate a GML definition of SRS to a usual format (e.g. WKT or PROJ.4)?

From GDAL 1.9.0 a new utility is available: gdalsrsinfo. Although it can yield an XML (GML-based) definition from a source equivalent format or file, it seems that it can only read usual GDAL/OGR ...
2
votes
1answer
2k views

Converting Raster Data to Polygon data

I am trying to convert a raster data to polygon data. Previously I was using the shapefile.py to create point data on individual lat/lon on the raster. But that will create a Huge data and querying it ...
0
votes
2answers
145 views

gdal_translate made wrong tranforms

I have a geotiff file in UTM and units in meters. I used gdal_translate with this command : gdal_translate -of GTiff -a_nodata 0 -a_srs EPSG:4326 old.tif new.tif gdalinfo on new.tif shows that the ...
6
votes
2answers
604 views

What Open Source (command line/API) method is there to orthorectify and georeference an aerial image given telemetry data?

How can I take an image and orthorectify it automatically with open source software? The information associated with each image is: camera specs latitude, longitude, elevation of the camera ...
3
votes
3answers
1k views

Viewshed Analysis With GDAL

I am looking to perform a simple (one observer location) viewshed analysis on a standard DEM using GDAL (either python or .NET bindings). I have searched, but haven't found any readily available ...
2
votes
1answer
262 views

Crop collar from chart

I need advice on how to complete the following task: I have aeronautical charts covering parts of the US (example: http://aeronav.faa.gov/content/aeronav/sectional_files/Albuquerque_89.zip - Each ...
5
votes
2answers
937 views

Creating a multispectral image from scratch

I want to make a multispectral image from cero to do some tests on it. Something really simple like 5 completely uniform bands with salt and pepper noise on them or a square of different values at the ...
6
votes
1answer
2k views

How to get GDAL to create statistics for GTiff in Python

I regularly create my own GeoTIFF rasters with GDAL in Python, e.g.: from osgeo import gdal from numpy import random data = random.uniform(0, 10, (300, 200)) driver = gdal.GetDriverByName('GTiff') ds ...
7
votes
4answers
1k views

Are there GUI resources for gdal and ogr?

For those who are new to the programming side of GIS, I feel that a lot of great tools and resources are inacessible. I am interested in GUI based wizards for handling geoprocessing with libraries ...
9
votes
5answers
6k 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 ...
1
vote
1answer
184 views

gdal_retile - Out of range band requested

I'm using gdal_retile to create ImagePyramid from a set of GeoTIFF images. I'm using following command: gdal_retile.py -v -r bilinear -levels 8 -ps 2048 2048 -co "TILED=YES" -co "COMPRESS=JPEG" ...
5
votes
2answers
610 views

GDAL - Perform Simple Least Cost Path Analysis

I am investigating methods to perform a simple least cost path analysis with gdal. By simple, I mean using the slope of a dem as the only cost factor. I would prefer to do using the python or .net ...
2
votes
1answer
1k views

Convert area from square meters to degrees globally

I have a global raster file with 3600x1800 pixels. I don't have any information about the projection used. The raster contains one band with a quantity with the unit "per square meter". How can I ...
0
votes
3answers
352 views

raster data retrieval from postgis using c++

I have raster data in a postgis server (I am able to see it in qgis). When I retrieve it and form gtiff image out of it using gdal, the generated image is not correct (there is a coloring problem). I ...
3
votes
1answer
175 views

how to square the pixels of a GeoTiff

I have a GeoTiff that has been supplied to me with non square pixels (I suspect due to reprojection to lat lon at some point). However the next step in my processing chain requires a Arc ASCII grid as ...
5
votes
2answers
504 views

Tiling high resolution image using GDAL tools

I have a .tif image that I georeferenced using QGIS utility. It was originally in UTM with NAD83 as datum. I need to make tiles out of it and get a kml file to overlay onto google earth. Here's how I ...
1
vote
1answer
103 views

Can I avoid runtime raster interpolation by creating an image pyramid to match the zoom scales?

For image quality and performance reasons, it would be best to perform interpolation of my large TIFF image of the world (10GB) beforehand to all the zoom scales I need to display at so that MapGuide ...
3
votes
2answers
335 views

Eliminate small polygons from shapefile

I downloaded GTOPO30 *.DEM files, and extracted a contour line at 2000m altitude using gdal_contour. In the resulting shapefile, I have many small polygons in areas where the altitude is close to that ...
1
vote
1answer
371 views

GDAL: Raster Intersection

I have two raster layers. (A) is state-sized, 30m. (B) is county-sized, 3m. I'd like to get a new raster (C) which is the part of (A) which coincides with (B), preferably scaled to the same ...
3
votes
1answer
1k views

How to use gdal_contour in QGIS Python console?

Is there a way to use the gdal_contour utility with-in the python console of qgis ? Thank you
2
votes
1answer
674 views

Filtering a raster by pixel value ? (Qgis)

I have downloaded Globcover data in GeoTIFF format. I want to create a new grid which only has values where the Globcover data (the only band in the TIF file) has one certain value (==190). Can I do ...
10
votes
1answer
990 views

Understanding the Map Tile creation properties

I am trying to create a tile base map. I have an image that I want to create the tile from and I am using GDAL. I managed to create the tiles but when I view the result it seems that the tiled map ...
3
votes
1answer
606 views

how do I get the “outer mantle” of a polygon shape file? (without joining all the polygons)

I am interested in finding all the vertices of all polygons which are not on the inside the most outer polygoin that can be formed in a shape file: Here is how I get all the vertices: def ...
5
votes
2answers
2k views

How to georeference using GDAL tools?

I have a .tiff image that I am trying to overlay in google earth. For that I require to georeference it first. The image projection is UTM with NAD83 as datum. I know the lat/long of the four corners ...