Robust two-dimensional weighted and unweighted phase unwrapping that uses fast transforms and iterative methods

This provides a weighed phase unwrap. It is a replication/re-implementation of Ghiglia, Dennis C., and Louis A. Romero. "Robust two-dimensional weighted and unweighted phase unwrapping that uses fast transforms and iterative methods." JOSA A 11.1 (1994): 107-117. in Python, depending on Scipy and numpy for performance.