I'have been trying to convert band 7 (precipitation) of a grib file (you can download it if you like) to a visible PNG image which I can load via KML into a google maps viewer I have.
The precipitation of the grib displays just as I'd like to see it inside quantum gis if in Layer properties I choose to render band 7 as single band gray with a pseudocolor color map. Furthermore specifying 0 for nodata values.
I have tried using this command with gdal (version 1.9.2-2~precise4):
gdal_translate -a_nodata 0 -of PNG -b 7 grib.grb2 grib.png
but the resulting grib.png 's size is just 295 Bytes and it is just transparent when opened in a viewer.
I need someone to explain to me how to do this and why. And if you know other command-line tools which work to convert this file, that'll help, too.