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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1answer
102 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
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1answer
384 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
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2answers
217 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
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2answers
170 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 ...
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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 ...
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2answers
160 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?
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1answer
302 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
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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" ...
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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
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1answer
62 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 ...
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0answers
77 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
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2answers
293 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 ...
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0answers
92 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 ...
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0answers
201 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 ...
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0answers
467 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 ...
2
votes
2answers
114 views

Invert gdaldem aspect

I am trying to identify lakes and other water bodies in a DEM file. The source file is located here. I am using gdaldem aspect to identify contiguous pixels with zero slope change. gdaldem aspect ...
2
votes
1answer
232 views

KML to shape QGIS conversion [duplicate]

I am trying to import a KML file to QGIS. The KML source file is about 15mb is comprised of polygons with attribute data. The KML imports fine and polygons display but the attribute data is unreadable ...
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2answers
940 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 ...
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0answers
842 views

How do I change from lat/long to a metric coordinate system in GRASS?

Yes, it's yet another transformation question. I am working with ASTER DEM data, which is LatLong WGS84. I want to process the DEM map into an STL file for use in a CFD simulation. The script I am ...
8
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1answer
266 views

Python with GDAL and PostGIS as a replacement of ArcGIS

Few times ago, I worked with daily land surface temperature satellite images of an area with the size of Alaska. I had to process around one thousand images. I downloaded them, mosaiced, projected, ...
2
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2answers
397 views

How to use gdal module in python

I am trying to import gdal modules from osgeo installed in my win64x machine but I get the following error: Traceback (most recent call last): File "", line 1, in from osgeo import ogr ...
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0answers
442 views

How to properly convert EPSG:3857 to EPSG:4326 tif?

I tried using the answer from "Transforming EPSG:3857 to EPSG:4326" to do this but gdalinfo tells me that this didn't really work properly. Driver: GTiff/GeoTIFF Files: geo-map.tif Size is 1024, 512 ...
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2answers
2k views

No ogr module despite having gdal installed?

I am trying to use the mapping component of the wonderful PySAL package, but for some reason I do not have the ogr module. I was under the impression that it came packaged with gdal. Am I missing ...
2
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0answers
344 views

GDAL: Geotransform - rotated rasters (and ArcGis)

I am working on a GDAL driver for a proprietary grid-format. In some cases, the grids are rotated in order to get smaller file sizes. In my GDAL geotransform array, I do the following (showing a ...
0
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1answer
53 views

USGS FLT Hdr file interpretation

I have a legacy program that attempts to read USGS 1/3 arcsec data. When I compare results to GDAL, I find that the lat/lon to pixel conversion is off by 1 line. The reason (I think) is because the ...
2
votes
2answers
159 views

OSM linestring shown as point

I have loaded the following file http://openstreetmapdata.com/data/coastlines to postgreSQL. In visual studio with gdal/ogr and geos enabled: SELECT geom FROM waterpoly WHERE geom IS NOT NULL LIMIT ...
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0answers
178 views

GeoPDF Support in GDAL

I installed OSGeo4W using a Windows installer... it contains GDAL 1.7.3. I can't get GDAL to recognize PDF as a file type using commands in MSYS shell. Does this version of GDAL not support PDFs? ...
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2answers
461 views

gdal_calc.py outputs huge files

I think this is a general enough question to apply to more than just gdal_calc, but perhaps not. When I run gdal_calc.py -A map.tif --outfile=deforestation_00-10.tif --NoDataValue=0 --calc="A >= ...
3
votes
1answer
120 views

is it possible to project a shapefile to a raster's custom projection with command line gdal/ogr?

I have a raster with a user defined sinusoidal projection and a shapefile in lat/lng coordinates (I believe this is called 'unprojected'?). I'd like to use ogr/gdal's command line utilities to ...
1
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0answers
70 views

How can I maintain MapInfo GRC file attributes in QGIS/GDAL?

I am trying to manage a classified MapInfo grid file in QGIS - I'm wondering if anyone has any experience with maintaining the attributes of the classified grid? QGIS seems to assign them just a ...
3
votes
1answer
260 views

Best way to visualize the PostGIS Raster in OpenLayers

I have been stuck by this problem for a long time. Several ways have already been tried, but none of them works as I was expecting. Here are the description of each of these method as well as the ...
4
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1answer
552 views

Converting WMS getmap request to Geotiff

I'm accessing a WMS server that doesn't provide geotiff as one of the format capabilities, but does provide PNG and KMZ. ...
2
votes
1answer
721 views

Polygonize.py outputs into a single file or simple merge?

Given an unique raster topographic file at start, I want to get vector polygons for elevations thresholds 1m, 200m, 500m, 1000m, 2000m into a single shp file. I first slice my raster into 5 (or more) ...
0
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1answer
334 views

Polygonize.py: AttributeError: 'NoneType' object has no attribute 'CreateDataSource'

Given a topographic raster tif of an european country where elevations are simplyfied to either 0, either 200. How to create a polygon ? Comment: With the following polygonize.py command: ...
0
votes
1answer
310 views

How to conditionnally assign a new value to pixels of a raster image?

Given a topographic GIS raster of one country crop.tif: Given a know pixel value such as elevation (z) is +73 : $ gdallocationinfo crop.tif 1 1 -valonly > 73 Given an elevation threshold n = 50 ...
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2answers
300 views

Gdal: How iterate through all pixels of a raster image?

Given a topographic raster image. How to iterate through all pixels of this raster image ? Solution preferably with gdal, in console. Some other libraries/script could be installed. Related: ...
0
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1answer
333 views

Gdal: How to get a pixel's value from raster image?

Given a topographic raster image. Given a pixel's coordinate in pixel/lines or geocoordinate. How to get it's pixel value ?
0
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1answer
160 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 ...
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0answers
349 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 ...
2
votes
1answer
87 views

Revert back from RGBA raster to original 1 band raster cell value

I have a number or single band raster grids that have been converted to RGBA (png). I no longer have access to the orignal single band raster data but have the png files. Is there a way to convert the ...
1
vote
1answer
300 views

Error during conversion of shapefile to MySQL using ogr2ogr

I have installed MS4W in Windows 7. I get an error when I try to convert a shapefile to MySQL database using GDAL/OGR ogr2ogr. This is the command I'm trying: C:\ms4w\tools\gdal-ogr>ogr2ogr -f ...
0
votes
1answer
80 views

Why are some features missing from Raster menu in QGIS for linux?

I am running QGIS 1.8 in Ubuntu/Linux (13.04), with GDAL 1.10 installed. There seem to be features missing from GDAL tools that are present in Windows version. For example, I can't find Rasterize or ...
0
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1answer
190 views

What are the differences between the photometric options for GDAL_merge?

I am using GDAL_merge to merge several geotiff tiles into one large tile. One of the creation options I can add is photometric. There are several options for this. MINISBLACK MINISWHITE RGB CMYK ...
2
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0answers
279 views

QGis Save Raster as Rendered Image

In QGIS 1.9.0 Master, when you right click on a raster in the Layers Panel and select "Save As", you can select the output mode to be "Raw Data" or "Renedered Image". When selecting the Rendered ...
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2answers
219 views

gdal_translate syntax windows command line

I am trying to extract a band from a MODIS hdf file on windows with gdal_translate. Here's my prompt: gdal_translate -of GTiff ...
0
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1answer
158 views

OGR2OGR workaround for gpx-json conversion bug

ogr2ogr produces invalid GeoJSON when multiple layers are involved (http://trac.osgeo.org/gdal/ticket/3842). For example: ogr2ogr -f GeoJSON "$f.json" "$f" tracks routes For me the bad GeoJSON ...
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0answers
266 views

gdal2tiles.py problem - creating mini tiles

I have a similar problem to the issue posted here (gdal2tiles problem). I have 80 GeoTIFFs (4000x4000) with EPSG:27700 projection embedded and TFW and PRJ files. These I have built into a virtual ...
1
vote
1answer
117 views

Gdal image georeferencing and gdal2tiles image flip question [duplicate]

I'm georeferencing an image using gdal and the following command: gdal_translate -of Gtiff -co tfw=yes -a_ullr 0.016264915466308594 51.505109712517786 -0.0024890899658203125 51.492018739579336 -a_srs ...
0
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0answers
283 views

GDAL/OGR to extract pixel values

I want to use GDAL/OGR to extract pixel values from a raster file. The extraction should be based on polygons, stored in a shapefile. My thought was to iterate over the features in the shapefile, ...
1
vote
2answers
185 views

Optimising Min/Max temporal raster search in python/gdal

I need to search across ~100 1200x1200 raster tiles and produce a min and a max raster. Along the way i also want to exclude values that are over 1 or less than 0. What would be the quickest method to ...