It's hard to answer this without your specific file. You should look into producing reproducible, especially if you're posting to the R board. For R, check out library(raster) and library(ncdf4). I just grabbed the first grib1 file I saw, and put together a quick example. Library(raster) library(ncdf4) download.file(url = 'ftp://ftp.hpc.ncep.noaa.gov/grib/20130815/p06mf030.grb', destfile = 'test.grb') (r.
Installer exposure blend gimp. Maximize local contrast is one these scripts. This is content aware like Gimp plugin to remove objects from photo by synthesizing surrounding texture over the top of it.