Install gimp-normalmap by entering the following commands in the terminal:
sudo apt update sudo apt install gimp-normalmap
Description:
Normal map plugin for GIMP
This is a plugin for GIMP version 2.0+. It allows you to convert images into RGB normal maps for use in per-pixel lighting applications. The goal is to completely clone NVIDIA's photoshop plugin, with a few new useful features.
Homepage: http://code.google.com/p/gimp-normalmap/
Version: 1.2.3-0ubuntu5
Section: universe/graphics