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
votes
1answer
215 views

gdal2tiles generates small picture inside 256x256 tile

I've used gdal2tiles for generating tiles in number of different polar projections and always experienced the same problem — strange small picture inside normal 256x256 png with the rest of space ...
2
votes
1answer
998 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 ...
1
vote
2answers
1k views

Import error:No module named _gdal

I have installed python 2.5.1 and FWTools2.4.7 in my laptop(Windows 7) when i run my pythonscript in FWTools i get following error Import error:No module named _gdal can any one suggest how to solve ...
1
vote
1answer
468 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 ...
1
vote
1answer
1k views

Python GDAL: degrees to meters without reprojecting

I am trying to get senseful results in my Python script. I want to measure distance between features in a shapefile. I'm working with the SRS: GCS_WGS_1984, so my units are in degrees. But for the ...
1
vote
3answers
4k views

Convert Lambert Conformal Conic to WGS84

I am trying to convert my "Lambert Conformal Conic map with 2 standard parallels" to the basic/standard WGS84 projection that Google Maps use. I have 30 of these maps which I need to convert. They ...
0
votes
1answer
334 views

Creating records in output shapefile using Python

I have a list (output from a previous loop) containing attributes from an input shapefile. What I am stuck with is inputting those attributes to a new shapefile. I have plotted the point data using ...
0
votes
1answer
1k views

Missing QGIS raster menu tools - '“osgeo [python-gdal]” module is missing'

I recently had to reinstall QGIS (version 2.2.0-9) and the raster menu is missing its tools. I understand that the GdalTools plugin must be installed and enabled. I have already installed the GDal ...
24
votes
2answers
1k views

A comprehensive, user-friendly GDAL manual?

I'm becoming a real fan of using GDAL tools in a bash terminal. However, I quite often get stuck trying to solve particular problems, or getting syntaxes right. Apart from the details provided in the ...
10
votes
6answers
2k 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 ...
12
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 ...
7
votes
2answers
976 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 ...
10
votes
2answers
10k views

Converting projected geoTiff to WGS84 with GDAL and Python

Apologies if the following question is somewhat stupid, but I am only VERY new to this whole GIS thing. I am trying to convert some projected geoTiff images to WGS84 using gdal in python. I have ...
7
votes
2answers
2k views

Convert timeseries stack of GTiff raster to single NetCDF

Moving from gdal-dev mailing list: On Mon, Sep 2, 2013 at 7:09 PM, David Shean wrote: Hi list, I'm trying to package a timeseries of GTiff rasters with identical projection/extent/resolution as a ...
14
votes
2answers
2k views

Good practice for generating contours from a DEM

We have just received a large set of DEMs at work and I would like to generate contours from them. The DEMs have a resolution of 1m and a size of 1kmx1km. Output from gdalinfo: Driver: ...
9
votes
7answers
3k views

how to overlay shapefile and raster?

I have a shapefile with polygons. And I have a global raster file. I want to overlay the shapefile's polygons onto the raster grid and calculate the mean raster value for each polygon. How can I do ...
9
votes
3answers
3k views

Make the nodata area of a resampled orthophoto overview white?

I have a set of orthophoto images which are each fully filled with data, but when placed together the coverage does not form a rectangle so there are nodata areas. In MapGuide, I need to be able to ...
8
votes
2answers
273 views

Migrating from ArcGIS to gdal

I would like to collect a table of equivalent or close enough gdal based functions to replace ArcGIS functions (esp in spatial analyst). Are there functions available using gdal to perform the ...
8
votes
4answers
2k views

Performance of google map tile creation processes

I know that question is rather vague but please bear w/me. I'm trying to get an idea of what sort of product performance - specifically timing - people have seen for various methodologies they have ...
7
votes
1answer
1k views

gdalwarp, cutline and postgis

I can not figure out how I directly can read a polygon into gdawarp's -cutline argument. My current approach is: ogr2ogr -f "ESRI Shapefile" mydata.shp PG:"user=myuser dbname=gisdb" -sql "select * ...
9
votes
3answers
266 views

How to create composite hillshade?

The concept of composite hillshade is to combine multiple hillshades with different sunlight orientation to avoid blind spot. It requires to merge 3 hillshades images with 315⁰ (NW sunlight, default ...
6
votes
1answer
798 views

Subsetting GeoTIFF with Python

I'm sub-setting a GeoTIFF with the GDAL Python binding and numpy. Essentially, I am providing a central location (coordinates of a flux tower) from which I produce a subsetted image. I then want to ...
6
votes
2answers
820 views

How to add GDAL to existing Python installation?

I would like to download and install GDAL for Python version 2.6 [MCS v.1500 32 bit(Intel)] on win32 that supports reading FileGDB's with Python. But I am not sure how to go about this. I found one ...
6
votes
3answers
1k views

GDAL and Geospatial PDF on Windows

GDAL 1.8 now supports reading GeospatialPDF, see pdf format description page. Using it depends on the poppler pdf library. What is the smoothest route to getting gdal and geospatial pdf working on ...
5
votes
1answer
3k views

GDAL VRT Format - do i understand the concept?

Okay, so im a little fed up with different raster-in-database solutions that I tried over the last 2 weeks which don't work currently (Postgis raster) or cant handle my volume of data (Rasterlite), so ...
4
votes
1answer
5k views

Transforming EPSG:3857 to EPSG:4326

I am new to gdal and have a simple question. I want to transform an image from OpenStreetMap projection to Nasa Blue Marble projection. What I understand is that OpenStreetMap projection is EPSG:3857 ...
2
votes
1answer
1k views

How to add a color table to a one band tiff using GDAL?

I have 1-band GeoTIFF file. The color interpretation for band is gray. I want a color table in order to transform my Col.tiff to Col.jpeg or Col.png. I tried putting a color table in this tiff via a ...
13
votes
3answers
8k views

How do I change geotiff “no data” color to white/transparent rather than black?

I am preparing data for inclusion into a geonetwork node, where the maps are displayed via geoserver. The problem is that cells that have"no data" are displaying as black in the geotiff and I am ...
8
votes
2answers
1k 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, ...
7
votes
2answers
680 views

Conflict between ArcPy and GDAL/OGR?

TL;DR I can't get an installation free version of GDAL/OGR to work from within ArcMap 10.0. I get an ImportError: DLL load failed on _mod = imp.load_module('_gdal', fp, pathname, description). ...
7
votes
3answers
3k views

How to extract slope from topographic raster map?

I am working on a project for a machine learning class wherein I extract features from a topographic raster map and then classify the traversability of the terrain. One of the features I need to ...
7
votes
2answers
3k views

How can I turn a shapefile into a mask and calculate the mean?

I have been using python to process huge arrays stored as netcdf files. I would like to calculate the mean of an area defined by a shapefile. I have just installed GDAL but if there are other tools I ...
6
votes
2answers
793 views

What's a good toolchain to reproject some PNGs in plate carre to UTM?

I have some PNGs produced from Canadian DEM data. They're 1201px by 1201px heightmaps. Each one represents one quarter of a degree latitude and one quarter of a degree longitude. But I want to work ...
5
votes
5answers
2k views

Create a ground overlay kml from georeferenced raster

I have a world georeferenced raster (5m resolution, ~4000 x 4000 pixels) that I would like to display in google earth. I am looking for a simple and effective way to generate this kml file. Using ...
4
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 ...
4
votes
1answer
676 views

Raster data array output flipped on x-axis using python/gdal?

I'm trying to create a raster using the python gdal libraries and I've gotten to the point where data is being output, but the output data is flipped on the origin point's x-axis. I know I must be ...
3
votes
1answer
129 views

Are there examples of high-level interfaces to NetCDF

The R raster package and GDAL both have independent wrappers around NetCDF-4* that treat an array variable as a "complete" dataset, i.e. they provide objects or interfaces that seamlessly give access ...
2
votes
1answer
4k views

Python GDAL: Save array as raster with projection from other file

I have an array of data, and for each datapoint I know the latitude and longitude. I'd like to save it as a GTiff with the same projection as other rasters I have. This is what I've tried so far, but ...
2
votes
1answer
360 views

GDAL 1.9.1 ogr2ogr KML to PostGIS not incuding ExtendedData

I have a KML file utilizing a Schema in the document and ExtendedData in each placemark. The ExtendedData does not seem to pass in conversion to PostGIS or shapefile. Any assistance would be much ...
2
votes
2answers
959 views

GDAL Clipping (hack)

I am trying to use the python script from http://www.sparkgeo.com/labs/2010/07/07/gdal-clipping-hack/ to clip a raster based on many shapefiles. The script is using a mysql database an i would like to ...
1
vote
1answer
110 views

How do I convert a TIF to EPSG:3857

I'm trying to convert this TIF to EPSG:3857, but when I run: gdalwarp -of GTiff -s_srs epsg:4326 -t_srs epsg:3857 -co "tfw=yes" original.tif converted.tif I just get a black TIF do you know what I ...
1
vote
2answers
920 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 ...
1
vote
0answers
581 views

Topography: How to convert raster into vector layers?

(nb:This project is part of the #Wikipedia #wikimaps project) 1. Question: How to create vector topographic maps from raster image ? How to convert raster topographic image into closed vector ...
15
votes
1answer
1k views

How to rename field names in a shapefile from the commandline?

I need to rename the field names (attributes) in a shapefile. Is there an easy way to do this from the command line?
13
votes
3answers
8k views

ogr2ogr converting to shapefile - how to select feature types?

Shapefiles can only have one geometry type, but many other formats (kml, geojson) can have multiple types. When converting to shapefiles, is it possible to to tell ogr2ogr to create multiple ...
8
votes
6answers
956 views

How do I generate thumbnails images from lots of shapefiles?

A colleague and I recently released an Open Source project called Mapoteca which is a set of Python Scripts that integrates with a GDAL/FWTools installation allowing a full walk-through of directories ...
7
votes
2answers
622 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 ...
7
votes
2answers
6k views

How do I convert affine coordinates to lat/lng?

I am extremely new to GIS. I'm using gdal to read in a landuse/landcover map and I need to pick out the lat/lng of certain land cover types to index into a different dataset which is expressed only ...
6
votes
1answer
1k views

What tile/tiling strategy should I use with GeoNode/GeoServer?

I've got a wicked GeoNode instance running, loaded with some basic vector data. I want to be able to serve our local-County aerial imagery as a basemap within GeoNode. I am thoroughly overwhelmed with ...
5
votes
2answers
893 views

Error exporting data from Oracle to shp using ogr2ogr

I have an oracle table which I would like to query/make a selection. I would then like to export the selection to a shp file. I'm using gdal and ogr2ogr. Following the guidelines here and here I ...