Substance Alchemist splatter filter. It lets you scale and tile your material, with parameters and options as:
Height refinement (low pass, slope balance, high pass, smoothness).
Edge feathering (hides splat seams).
Edge feathering radius.
Sharpen by halo maps.
Debug view to visualise splats.
This filter works best with organic materials such as ground types, dirt etc. It can work on just a single image run through the bitmap to material filter, or with entire scans. The images I used with it were shot with my mobile phone (Galaxy S7) in less than ideal conditions, and used as JPEG. Pretty sweet results still!
The filter is for sale on my Artstation Store as well: https://www.artstation.com/kayv/store/OWg9/alchemist-splatter-input-filter-one-splat