This plugin expands upon the Resynthesizer plugin to synthesize tilesets. It requires that plugin installed. Tested with GIMP 2.8.
Install GIMP 2.8 and the Resynthesizer plugin, found at https://github.com/bootchk/resynthesizer or http://www.logarithmic.net/pfh/resynthesizer.
Then copy plugin-resyth-tileset.py to your plugins directory (which
can be found in GIMP's Preferences > Folders), and restart GIMP.
Delete the files added in installation.
Resynth Tileset works much like the base Resynthesizer in texture transfer mode. It expects a sample image, and input output maps describing how to map parts of the sample to the output. However, now the output map must be in an expected format, a 10 by 5 layout of tiles.
Use Filters > Tileset > Generate Resynth Tileset Output Map to
generate an example output map with the right format. It can be edited
further to customize the output, before running Filters > Tileset > Resynth Tileset
to generate the actual image.
Further explanation can be found in the wiki on github: https://github.com/boristhebrave/resynth-tiles/wiki
This code is licensed under the GPL3 copyright Adam Newgas 2013.