This script simulates a high quality (portrait) photo like these from the National Geographic.
Copy it into the scripts folder from GIMP, you will find it then under Filters → Generic → National Geographic.
Thanks to Martin Egger for the shadow revovery and the sharpen scripts, which I included in the script.
Examples here and here:
Updates:
gimp -i -b '(elsamuko-national-geographic-batch "picture.jpg" 60 1 60 25 0.4 1 0)' -b '(gimp-quit 0)'
gimp -i -b '(elsamuko-national-geographic-batch "*.jpg" 60 1 60 25 0.4 1 0)' -b '(gimp-quit 0)'