Good day Curtis,
most if not all one needs to know about Orientation Salience Functions—theoretical and algorithmic aspects—is explained in the above cited papers. Algorithmic realization with high precision isn’t trivial but the steps are well explained and a link to an ImageJ-plugin is given. However, the latter doesn’t do all of the job …
Be aware that the approach acts globally or regionally but not locally as “Structure Tensor”-analyses do.