The main algorithm (PatterMatch) was developed by Connelly Barnes, a Princeton grad student, who as interned at Adobe multiple times.

Read his original PhD thesis on "PatchMatch: A Randomized Correspondence Algorithm for Structural Image Editing" http://gfx.cs.princeton.edu/pubs/Barnes_2009_PAR/index.php

As well as the follow up paper with collaboration from Adobe: "Video Tapestries with Continuous Temporal Zoom" (published at SIGGRAPH) http://gfx.cs.princeton.edu/pubs/Barnes_2010_VTW/index.php