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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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 ...
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1answer
382 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 ...
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1answer
394 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 ...
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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 ...
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1answer
818 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 ...
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2answers
868 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
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1answer
316 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 ...
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3answers
457 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 ...
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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
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2answers
454 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 ...
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1answer
358 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 ...
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1answer
541 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
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1answer
564 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
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1answer
881 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 ...
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3answers
354 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
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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 ...
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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 ...
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2answers
599 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 ...
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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
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1answer
259 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
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2answers
930 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
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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 ...
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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 ...
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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 ...
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1answer
182 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" ...
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2answers
602 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
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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 ...
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3answers
350 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
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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
502 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 ...
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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
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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 ...
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1answer
365 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
997 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
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1answer
666 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
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1answer
985 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
598 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 ...
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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 ...
7
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2answers
6k views

ECW for QGIS 1.8 in Ubuntu 12.04

I have followed various online help guides on how to make ecw for QGIS 1.8 work in Ubuntu 12.04. I had it all working in Ubuntu 10.04 but since migration to 12.04 no such luck. Is there a guide that ...
10
votes
1answer
396 views

OGR/GDAL threading results in low core utilization

I'm trying to process some raster data using ogr/gdal and I can't seem to get full utilization of all the cores on my machine. When I only run the process on a single core, I get 100% utilization of ...
2
votes
1answer
399 views

How to add GDAL Programs folder to ~/.bash_profile

I have recently installed on Mac OS X Lion 10.7.4 the GDAL Framework 1.9 with Python bindings from [http://www.kyngchaos.com/software:frameworks][1]. I need to add the following Programs folder to my ...
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1answer
828 views

TMS format specification

I want to convert large map file to tms format. how directory structure, zoom levels , tile size, xml file creation have to be dealt with. Please point to the relevant docs. And is there any gdal c++ ...
4
votes
1answer
687 views

GDAL: How to build an image pyramid starting from the base

Normally I would create an Image Pyramid using gdal_retile.py on one large image or a set of large images. I want to do the opposite. I have all the zoomed in tiles on the base level and I want to ...
5
votes
1answer
332 views

Mosaicing indexed colour rasters with independent colour tables

I have a large number of single band rasters that are colour indexed TIF files. I want to mosaic them using GDAL (or similar non-proprietary software with a Python API I can call as part of a bigger ...
3
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1answer
636 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
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1answer
273 views

gdalinfo gives no georeferencing information for a PostGIS raster

I have a PostGIS raster dataset which I am trying to access via GDAL. I've had various problems with making this work, so thought I'd try running the gdalinfo command to check that GDAL can actually ...
3
votes
1answer
298 views

GDAL minidriver and Tilecache

I'm trying to use GDAL minidriver to read tiles folders generated from Tilecache seeding. I have set this in my GDAL source <ServerUrl>http://myserver.com/test/${z}/${x}/${y}</ServerUrl>, ...
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1answer
356 views

Rasterize difference between QGIS and FWTools

I am wanting to use FWTools to rasterize a large number of Shapefile polygons. I have used the Rasterize tool in QIS and it works great. But when I use the generated code in FWTools the process does ...
3
votes
3answers
2k 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 ...
5
votes
3answers
1k views

How to generate colorful images using GDAL?

I am using gdal_translate -of JPEG -scale -co worldfile=yes ndvi.tiff output.jpg command to convert tiff images to jpg and resize it. But it generates only black and white images. How can I generate ...