This addon for Blender allows for scattering image textures as seen here:
https://www.youtube.com/watch?v=xKnSgH8zVuA
It was developed for cgcookie.com, so if you are a CGC member you can download the addon here.
You can also find the addon on the Blender Market.
Or, read through the documentation.
This repository only stores the code for the addon and is used for tracking bugs and feature requests. In order for it to append the correct nodes to your project, it needs the accompanying .blend files that are included with the downloads in the links above.