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How to convert self intersecting polygon to multipolygon?
Working with the union and polygonize methods in GDAL/OGR, I often end up with self intersecting polygons. The case is one polygon which essentially consists of two polygons: In the above example, the...
View ArticleWhat is the correct syntax for using gdal_rasterize with a PostGIS datasource
I have a multipolygon layer in PostGIS and I would like to use gdal_rasterize to generate a raster. I cannot find the correct syntax to specify PostGIS as the data source. $ gdal_rasterize -a...
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circle detection on binary image
My image is gray scale image which i have converted to binary by smoothing and then edge detection method. Now i want to place the circle /ellipse on edge detected. I don’t know how to proceed further....
View ArticleHow can I call gdal_translate from Java code?
How can I execute gdal_translate in Java? For example, will something like this work? gdal_translate "PG:host=localhost dbname='xyzy' schema=public' table='xyz'" "d:xyxab.tiff"
View ArticleUsing the C++ GDAL API how do I set the GDAL_DATA path?
If I want to change the directory of the GDAL_DATA path or point to a different version of a csv file for EPSG numbers how do I do that using the C++ API?
View Articleinformations about “gdaltransform” utility of GDAL
I have a doubt about GDAL reprojection. I use “gdalwarp” utility to reproject an image in a specific projection system (for example WGS84 UTM49). “gdalinfo” on original image displays this corner...
View ArticlePython GDAL: find out spikes and pits in DEM
I’m working with on a DEM (Geotiff) in Python GDAL, and I’d like to find out the spikes or pits in my terrain. I have no idea how to proceed, does anyone have good algorithm to help me out? Thanks, eo
View ArticleHow to transform World data from EPSG 4326 to EPSG 3857
I have tryed different opensource tools to transform a world data shapefile from 4326 to 3857 but I always have an error. Im not sure, but is it because of Antartica? I have tryed with GDAL and QGIS...
View ArticleHow do I get the domain from an OGRSpatialReference?
I would like to know what the projected bounds are for a spatial reference using OGRSpatialReference. Is there some way to use the GetProjParm method to get this information? An example of what I’m...
View ArticleWhat's regular blocking arrangement ? (GDAL)
I am using GDAL tools to retrieve PostGiS raster. The code(command line) I am using is as follows : gdal_translate -of AAIGrid "PG:host=localhost dbname='database' user='postgres' password='admin'...
View ArticleGDAL Plugin with a different version of GDAL aready built into QGIS
My qgis windows version is 1.8.0 Lisboa and use the gdaltools in version1.9.2. I want to use the plugin NetCDFBrowser, but this plugin need the gdal 1.10. I install 1.10 stand-alone gdal find here...
View Articlepython gdal_polygonize error
I am trying to use gdal_polygonize to create a polygon from a binary raster. My code is: os.system('gdal_polygonize.py ' + filename + ' -f ESRI Shapefile ' + shapefile) where filename is a string file...
View ArticleWhat's the best way to add a projection to GDAL?
I have a number of files in Maryland State-Plane (US foot) that have the following wkt: “PROJCS["NAD_1983_StatePlane_Maryland_FIPS_1900_Feet", GEOGCS["NAD83", DATUM["North_American_Datum_1983",...
View ArticleMichigan Projection with GDAL or FWTools
Has anyone come across a specific projection for Michigan, specifically: NAD_1983_CORS96_StatePlane_Michigan_South_FIPS_2113_Ft_Intl When I look at spatialreference.org I do not find any instance of...
View ArticleInstallation of GDAL 1.10 in Windows 8 and Ubuntu 12.04
Is there an easy way to install GDAL/OGR 1.10 in Windows 8 and Ubuntu 12.04.
View ArticleBuild overviews before building tiles?
Does it make sense to create overviews (with gdaladdo) for my GeoTiffs (about 12000×15000 px) before creating tiles in GeoWebCache? Does resampling affect the quality of my tiles?
View Articlecut tiles with gdal2tiles.py from a png with world coordinate info
I have a collection of PNG files that use the standard google maps projection and have baked into the filename of each the zoom level (all of them are at 22), the x and y pixel coordinates of the...
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How can I translate Modis HDF To GeoTiff
I’ve a MODIS04 L2, and I want to extract band 8:Image_Optical_Depth_Land_And_Ocean. I use Quantum GIS to open this band, because Quantum GIS see this is not coordinates so this allow me to select...
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How to use GDAL for Translate Modis HDF to GeoTiff
I’ve a MODIS04 L2, and I want to extract band 8:Image_Optical_Depth_Land_And_Ocean. I use Quantum GIS to open this band, because Quantum GIS see this is not coordinates so this allow me to select...
View ArticleHow can I use GDAL to batch define a projection?
I have a fodler with 1500 ECW rasters, no spatial reference information defined. Can I use GDAL to batch define a projection for all 1500 in the folder?
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