I looked at this question How do I install Gimp 2.7?, but it wasn't helpful, as its solution was to just install gimp 2.6. Do I need to compile it from source in some way?
Follow this guide: Install GIMP 2.7.1 on Lucid Lynx using PPA
Good luck! :)
Follow this guide:
but used babl version 0.1.4, gegl version 0.1.6, and gimp version 2.7.3.