[gdal-dev] Grib2 band to Geo Tiff

[Chaitanya kumar CH]

James,

You can use the GDALDriver::CreateCopy() method to translate a dataset if
you don't plan to perform any reprojection during translation.
If you don't need the intermediate geotiff file, you can look at the
ogr2ogr.py [0] script to perform the reprojection and translation in one go.

[0]
http://trac.osgeo.org/gdal/browser/trunk/gdal/swig/python/samples/ogr2ogr.py

On Wed, Jan 19, 2011 at 6:56 AM, manzione
<james.j.manzione at usace.army.mil>wrote:

>
> Greetings and thank you for looking at my post,
>
> I am converting a Grib2 file into a geo tiff file and then reprojecting it
> in python.  When I reproject the tiff file it states it is "unable to
> compute a transformation between pixel/line and georeferenced coordinates"
> for my converted tiff file because "there is no affine transformation and
> no
> GCPs."
>
> I ran some tests and am under the assumption that my script is not
> embedding
> any georefferencing information into the tiff file.  Any suggestions on how
> to do this?  I am new to gdal and could use the help.  Below is my code for
> the conversion.
>
> Thank you in advance for your advice,
> -James
>
> Script:
>
>    dataset = gdal.Open( Rpath, GA_ReadOnly )
>
>    xsize = dataset.RasterXSize
>    ysize = dataset.RasterYSize
>    pixels = xsize * ysize
>
>    num_bands = dataset.RasterCount
>    for band_num in range(1, num_bands + 1):
>        band = dataset.GetRasterBand(band_num)
>        meta = band.GetMetadata()
>        bandName = str(meta['GRIB_COMMENT'].split()[0])
>        tiffImagePath = str(pngPath + bandName + '.tiff')
>
>        ct = color_table(str(table))
>
>        buf = dataset.ReadRaster( 0, 0, xsize, ysize, None, None, None, [
> band_num ] )
>        outBand = tiff.Create( tiffImagePath, xsize, ysize, 1, GDT_Byte)
>        if outBand is None:
>            sys.exit(1)
>
>        outBand.GetRasterBand(1).SetRasterColorTable(ct)
>        outbuf = []
>
>        for offset in range(0, pixels):
>            val = int(struct.unpack_from('d', buf, offset * 8)[0])
>            if val > 255: val = 255
>            if val < 0: val = 0
>            outbuf.append('%c' % val)
>        buffo = ''.join(outbuf)
>        outBand.WriteRaster( 0, 0, xsize, ysize, buffo, xsize, ysize,
> GDT_Byte )
>
> --
> View this message in context:
> http://osgeo-org.1803224.n2.nabble.com/Grib2-band-to-Geo-Tiff-tp5937919p5937919.html
> Sent from the GDAL - Dev mailing list archive at Nabble.com.
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>



-- 
Best regards,
Chaitanya kumar CH.
/tʃaɪθənjə/ /kʊmɑr/
+91-9494447584
17.2416N 80.1426E
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20110119/def1c33a/attachment.html