Just today I was looking at this little Gimp-Perl plug-in I wrote, so that I could instantly save my .XCF gimp working files as .png with a single hotkey.
It's a very basic example, I guess to apply it to your problem you'd want to call the plug-in-color-map function (found in the DB Browser), uncomment the undo group bits and so on. Then just stick it in /usr/lib/gimp/2.0/plug-ins (or wherever your plug-ins directory is).
As others have pointed out, ImageMagick is normally the way to go for this sort of thing. But of course, gimp offers a much richer image manipulation toolkit, so mastering the gimp is a worthwhile goal.
use Gimp;
use Gimp::Fu;
#Gimp::set_trace(TRACE_ALL);
register "pngify",
"Save this image as a PNG",
"Save this image as a PNG, so that you don't have to go throu
+gh million
s of dialogs.",
"Sam Vilain",
"Sam Vilain",
"1.0",
N_"<Image>/File/Save as PNG",
"RGB*, GRAY*",
[ ],
sub {
my($img,$drawable)=@_;
my $fn = $img->get_filename;
$img = $img->duplicate;
#eval { $img->undo_group_start };
$drawable = $img->flatten;
$fn =~ s{\.\w+}{.png} or die;
$img->file_png_save_defaults($drawable, $fn, $fn);
#eval { $img->undo_group_end };
undef;
};
exit main;
$h=$ENV{HOME};my@q=split/\n\n/,`cat $h/.quotes`;$s="$h/."
."signature";$t=`cat $s`;print$t,"\n",$q[rand($#q)],"\n";