2D simultaneous phase unwrapping and filtering: A review and comparison

In optical metrology, most phase demodulation methods recover the phase wrapped in the range [-pi,pi]. But actually the phase is a smooth surface that exceeds this dynamic range. Therefore, it is necessary to use a phase unwrapping method to recover the desired smooth phase surface. Here we show a performance between our Recursive Phase Unwrapping (RPU) system, the well known Goldstein branch-cut unwrapping method and the Regularized Phase Tracker (RPT). The RPU is a Infinite Impulse Response system that simultaneously unwraps and low-pass filters the wrapped phase. Unlike branch-cut methods, our RPU system does not need mark phase inconstancies for successfully unwrap the phase. We will see that the RPU is a novel practical, fast, and robust solution for the phase unwrapping problem in two-dimensions (2D). (C) 2012 Elsevier Ltd. All rights reserved.