[gdal-dev] New to list and question (UNCLASSIFIED)

[Jorge Arévalo]

2011/2/8 Lefman, Jonathan ERDC-TEC-VA <Jonathan.Lefman at usace.army.mil>:
> Classification: UNCLASSIFIED
> Caveats: NONE
>
> Thank you Jorge.  That worked.  :)
>
>

Good to hear it :-).

Adapted from http://trac.osgeo.org/postgis/browser/trunk/raster/scripts/python/raster2pgsql.py


>
> -----Original Message-----
> From: Jorge Arévalo [mailto:jorge.arevalo at deimos-space.com]
> Sent: Tuesday, February 08, 2011 11:15
> To: Lefman, Jonathan ERDC-TEC-VA
> Cc: gdal-dev at lists.osgeo.org
> Subject: Re: [gdal-dev] New to list and question (UNCLASSIFIED)
>
> Hi Jonathan,
>
> On Tue, Feb 8, 2011 at 4:46 PM, Lefman, Jonathan ERDC-TEC-VA
> <Jonathan.Lefman at usace.army.mil> wrote:
>> Classification: UNCLASSIFIED
>>
>> Caveats: NONE
>>
>> Hi all,
>>
>> I joined this list today.  I have a question about using Python
>> bindings with GDAL to get info from a geotiff.
>>
>> What are the functions that I need to obtain coordinate extents of
>> raster data?  For example, if I have a rectangular area from
>> Washington, DC with coordinates in UTM format, how would I determine
>> the top-left and lower-right corners?  I was unable to find an example in
> the documentation.
>>
>> Here's a snippet of my code of where I'm at:
>>
>> from osgeo import gdal
>>
>> gdaldata = gdal.Open(gtiff_filename)
>>
>> prj = gdaldata.GetProjection()
>>
>> trfm = gdaldata.GetGeoTransform()
>>
>> Thanks everyone,
>>
>> Jon
>>
>> Classification: UNCLASSIFIED
>>
>> Caveats: NONE
>>
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>>
>
> Test this:
>
> from osgeo import gdal
>
> def calculate_geoxy(gt, xy):
>    """Calculate georeferenced coordinate from given x and y"""
>    xgeo = gt[0] + gt[1] * xy[0] + gt[2] * xy[1];
>    ygeo = gt[3] + gt[4] * xy[0] + gt[5] * xy[1];
>
>    return (xgeo, ygeo)
>
> ds = gdal.Open(gtiff_filename)
> prj = ds.GetProjection()
> gt = tuple(list(ds.GetGeoTransform()))
> dim = (
> (0,0),(0,ds.RasterYSize),(ds.RasterXSize,0),(ds.RasterXSize,ds.RasterYSize)
> )
> ext = (calculate_geoxy(gt, dim[0]), calculate_geoxy(gt, dim[1]),
>           calculate_geoxy(gt, dim[2]), calculate_geoxy(gt, dim[3]))
>
>
> Best regards,
>
> --
> Jorge Arévalo
> Internet & Mobilty Division, DEIMOS
> jorge.arevalo at deimos-space.com
> http://es.linkedin.com/in/jorgearevalo80
> http://mobility.grupodeimos.com/
> http://www.twitter.com/jorgeas80
> http://gis4free.wordpress.com
> http://geohash.org/ezjqgrgzz0g
>
> Classification: UNCLASSIFIED
> Caveats: NONE
>
>
>



-- 
Jorge Arévalo
Internet & Mobilty Division, DEIMOS
jorge.arevalo at deimos-space.com
http://es.linkedin.com/in/jorgearevalo80
http://mobility.grupodeimos.com/
http://www.twitter.com/jorgeas80
http://gis4free.wordpress.com
http://geohash.org/ezjqgrgzz0g