Global and Local Phase Unwrapping Techniques: a comparison

We investigate the relationship between local and global phase-unwrappingtechniques. We demonstrate that both algorithms are based on line integrationof an estimate of the phase gradient: the former evaluates the integral alonga single path, and the latter averages integrals along many paths. This analysisis extended to the weighted case. We also give an interpretation of the errorscaused by an incorrect phase-gradient estimate in terms of path-followingintegrals.