The r.pi GRASS extension is now published and available through the GRASS extension repository. It provides a range of functionality and allows to easily analyze spatial patch attributes in GRASS. Patches are expected to be raster objects derived from remote sensing data and their spatial characteristics is written into a new spatial file for further analysis.
The list of functions outlined in our recent publication in MEE can be seen here. More functions are available in the r.pi package but not specifically mentioned.