Improved reliability-guided phase unwrapping algorithm based on the fringe modulation and second-order phase difference

摘要

The Mask Cut unwrapping algorithm, a cross between Goldstein's Branch Cut and quality-guided path following algorithm, is generally successful at unwrapping phase; but if no good quality map, wrong placement of branch cuts or bad phase-unwrapping path, it will fail to confine the errors to the low-quality regions and lead to the failure of phase unwrapping. To overcome these drawbacks, we propose a new reliability function (i.e. quality map) based on the fringe modulation (the visibility of the fringes) and second-order phase difference, and improve the reliability-guided phase-unwrapping algorithm. Considering the residues, we use the reliability information to guide the placement of branch cuts and to optimize the phase-unwrapping path. The simulated and experimental data both demonstrate the validity of the new reliability-guided phase-unwrapping method. (c) 2006 Elsevier GmbH. All rights reserved.