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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6answers
1k 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 ...
1
vote
2answers
986 views

How to extract subdataset from HDF raster?

I am trying to extract a subdataset from HDF raster. Later on, I intend to make operations such as mosaicking and extracting raster averages from the extracted subdataset. The following code is ...
14
votes
1answer
368 views

Why do people pronounce GDAL (Geospatial Data Abstraction Library) like goo-dal?

Ok, a bit of a silly question, but: I've heard people pronouncing the library GDAL (Geospatial Data Abstraction Library) like goooo-dal. My natural inclination was to pronounce it geeee-dal, as in ...
1
vote
1answer
171 views

GDAL reports no bands for a 12-band raster and no projection either

When opened in ArcGIS, the raster correctly unfolds 12 bands, but when I try to open it with GDAL through Python, it appears as a raster that has zero bands. Here is the code: import gdal from ...
1
vote
1answer
80 views

Which kind of grid format is this?

in a project I got some raster files with the following content (header and data are in one txt file): HOUR 17 MINUTES 30 YEAR 2012 MONTH 5 DAY 4 CITY Emilia;Bologna NROWS 99 NCOLS 156 ULXMAP ...
0
votes
1answer
138 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 ...
3
votes
1answer
439 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
votes
2answers
310 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
vote
2answers
216 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 ...
0
votes
1answer
75 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 ...
0
votes
2answers
190 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?
1
vote
1answer
420 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
votes
1answer
126 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" ...
-3
votes
1answer
84 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
votes
1answer
81 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 ...
1
vote
0answers
86 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
votes
2answers
562 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 ...
2
votes
0answers
109 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 ...
0
votes
0answers
285 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 ...
1
vote
0answers
606 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
132 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
316 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 ...
7
votes
2answers
1k 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 ...
2
votes
0answers
1k 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
votes
1answer
283 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, ...
1
vote
3answers
649 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 ...
1
vote
0answers
536 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 ...
1
vote
3answers
3k 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 ...
3
votes
1answer
469 views

Rotating rasters using GDAL Geotransform (and ArcGIS Desktop)

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
votes
1answer
56 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
194 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 ...
1
vote
0answers
200 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? ...
1
vote
2answers
668 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
150 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
vote
0answers
95 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
356 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
votes
1answer
698 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
1k 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
votes
1answer
486 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
454 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 ...
1
vote
2answers
396 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: ...
1
vote
1answer
441 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
votes
1answer
225 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 ...
1
vote
0answers
503 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
112 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
374 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
82 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
votes
1answer
230 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 ...
4
votes
1answer
383 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 ...
1
vote
2answers
250 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 ...