Enhancement strategy based on three-layer filtering for a single fringe pattern

Abstract

The quality enhancement of a single fringe pattern is a challenging task in speckle interferometry. Fringe patterns suffer greatly from three adverse variations (nonuniform background, speckle noise, and intensity modulation). In this Letter, we propose a three-layer filtering strategy for noisy fringe patterns. The first layer is aimed at high-frequency speckle noises and low-frequency background. The second layer is for remaining speckle noises distributed in the middle-frequency band. The third layer will further implement quality enhancement by a phase-recovery technique. The proposed strategy is quantitatively evaluated by different indexes and verified to be effective through numerous comparative experiments.