Re: [gdal-dev] Re: gdal_translate -unscale option

John, The 'unscale' operation computes the real value of that pixel. -90.8230819702148 is the value stored at the pixel. -200.277178508775 is the value of the pixel. On Tue, Jul 26, 2011 at 5:35 AM, jt2000 wrote: > Frank, > > Does the unscale option work as advertised? > > I have a raster with

Re: [gdal-dev] Re: preserving alpha channel data with gdal_polygonize.py

Then, you can run a separate command to process the non-alpha bands. You need two processes because there may not be one-to-one mapping of the non-alpha and alpha band polygons. Finally, you need to make intersections of the polygons in the two layers and store the values of the alpha band polygon

Re: [gdal-dev] Re: preserving alpha channel data with gdal_polygonize.py

John, gdal_polygonize script stores the common pixel value in a field for every polygon. By default it is named 'DN', which can be changed by specifying the fieldname option. You must use the alpha channel to polygonize. So you have to use the -b option to specify that and may have to use the -no

[gdal-dev] Re: preserving alpha channel data with gdal_polygonize.py

Thanks Jay, Ideally I would like the data to be in a column of the shapefile output so I can load it in the database and use it to query. With gdal_polygonize.py this doesn't seem possible so I was wondering what other options are out there. -- View this message in context: http://osgeo-org.180

Re: [gdal-dev] preserving alpha channel data with gdal_transform.py

What format do you want the alphas channel in after running gdal_polygonize.py? I ask because after processing you could open the input and read just the alpha band (band 4 I assume). Here is a short script framework that might get you started. Something like: from osgeo import gdal gdal.open(i

[gdal-dev] preserving alpha channel data with gdal_transform.py

I have a very large raster file with data in the alpha band. I need to vectorize it and associate band 4 data with resulting polygons. Is there anyway to preserve alpha channel data or get that data associated with vectorized file after using gdal_polygonize.py? -- View this message in context:

Re: [gdal-dev] Modis L1B SWATH: georef problem hdf to geotiff

It seems interesting I'll keep a note on this :) The question is how you can build a VRT mosaic directly from MODIS hdf files, because the problem is that you have to mosaic first and after that to transform them to the EPSG:4326 projection. If you transform them first and mosaic them after you mi

[gdal-dev] Re: gdal_translate -unscale option

Frank, Does the unscale option work as advertised? I have a raster with offset and scale set. Driver: GTiff/GeoTIFF Files: raster.tif raster.tif.aux.xml Size is 10295, 7735 Coordinate System is: PROJCS["unnamed", GEOGCS["unnamed", DATUM["North_American_Datum_1983",

Re: [gdal-dev] Help needed regarding SWIG Packaging

Hi Even, Thanks for the reply. I was trying out the way you suggested it. I created a master.i which %includes all the other .i files. Upon compilation I am facing anther issue. It is a trivial issue I guess but I am not able to figure out. The things is, compilation with swig is usually in follo

Re: [gdal-dev] Modis L1B SWATH: georef problem hdf to geotiff

anna, Nikolaos, after much experimentation I found something that seems to work. gdalwarp --config GEOL_AS_GCPS FULL \ -tps -geoloc -t_srs EPSG:4326 \ -te -119.88004906118 13.5092548294379 \ -92.6036641645677 34.7070050511582 \ HDF4_EOS:EOS_SWATH:"MOD02HKM.A2011169.1750

Re: [gdal-dev] Help needed regarding SWIG Packaging

Le lundi 25 juillet 2011 11:27:41, Vipul Raheja a écrit : > Hi, > > I am working on developing SWIG-Python wrappings for OSSIM, a tool for > satellite image processing. I wanted some help regarding the same since > GDAL uses Swig for the same. I am facing a problem regarding the > packaging. > >

[gdal-dev] Re: Draw map in Visual C++

Brian, There are various libraries that already support drawing spatial data. One of them is Mapnik (which supports symbology and annotation among other things). Take a look at their C++ drawing sample. If you want to draw things in a much lower level, you

Re: [gdal-dev] How to convert a GIF (being a grid with value in channel B from RGB) to XYZ?

If the transformation is just shifting and scaling you can set the GeoTransform element in the VRT file. You can scale the pixel values using the Offset and Scale elements. On Mon, Jul 25, 2011 at 5:24 PM, Stefan Keller wrote: > Hi Chaitanya kumar > > Many thanks for the hints. I kow VRT from OG

Re: [gdal-dev] How to convert a GIF (being a grid with value in channel B from RGB) to XYZ?

Hi Chaitanya kumar Many thanks for the hints. I kow VRT from OGR but was not sure if this works here too. What I'm still wondering is, how to accomplish the transformation. It's rather a coord. translation process not comparable to warping: > The GIF size (= grid size) is 400x400 pixel with a ce

Re: [gdal-dev] How to check if projections are the same?

Selon Paul Meems : > We use GDAL/OGR/Proj4 in our application: MapWindow GIS. > > We're testing the MapWinGIS.GeoProjection class. It's just a wrapper around > OGRSpatialReference class, so it's GDAL behavior infact. > > The test code: > > private void button8_Click(object sender, EventArg

Re: [gdal-dev] gdalbuilvrt segmentation fault

Selon Marco Nicoletti : > Dear all, > > I have got a problem using the GDAL tool gdalbuildvrt. > > I would like to join two DEMs sampled on the same grid which insist on the > same > geografical zone. > The first DEM has got some NoDataValue holes and I would like to feel them > with the values in

RE: [gdal-dev] building GDAL for Java with ECW support

Selon Nicolas Simon : > Hi, > Concerning convertion from MSVC .lib to GCC import library .a, > help could by find here > > > http://jrfonseca.planetaclix.pt/projects/gnu-win32/software/reimp/index.html Yes I know reimp, but AFAIR, it doesn't work well with C++ symbols, which th

[gdal-dev] gdalbuilvrt segmentation fault

Dear all, I have got a problem using the GDAL tool gdalbuildvrt. I would like to join two DEMs sampled on the same grid which insist on the same geografical zone. The first DEM has got some NoDataValue holes and I would like to feel them with the values in the second DEM. I ave used also the

[gdal-dev] Help needed regarding SWIG Packaging

Hi, I am working on developing SWIG-Python wrappings for OSSIM, a tool for satellite image processing. I wanted some help regarding the same since GDAL uses Swig for the same. I am facing a problem regarding the packaging. As of now I have developed SWIG-Wrapper interface files (.i Files) for 130

[gdal-dev] How to check if projections are the same?

We use GDAL/OGR/Proj4 in our application: MapWindow GIS. We're testing the MapWinGIS.GeoProjection class. It's just a wrapper around OGRSpatialReference class, so it's GDAL behavior infact. The test code: private void button8_Click(object sender, EventArgs e) { MapWin

[gdal-dev] building GDAL additional formats for iOS

I have the build_for_iphoneos.sh script from the Christopher Stawarz's pseudogreen website. After working through a few issues, it successfully installs GDAL. Now I would like to add things like ECW support, SID support, expat, libkml, and libcurl. I have downloaded the source code for most of t

RE: [gdal-dev] building GDAL for Java with ECW support

Hi, Concerning convertion from MSVC .lib to GCC import library .a, help could by find here http://jrfonseca.planetaclix.pt/projects/gnu-win32/software/reimp/index.html Nicolas > -Message d'origine- > De : gdal-dev-boun...@lists.osgeo.org > [mailto:gdal-dev-