Single fringe pattern with closed fringes demodulation using row by row scanners

Abstract

Sequential methods like the regularized phase tracker (RPT) are commonly used for fringe pattern demodulation with closed fringes. The only drawback of the RPT method is the necessity to implement a two-dimensional (2D) fringe following scanning in order to obtain the expected modulated phase. In this article we present a new method to demodulate single fringe patterns with closed fringes which use a simple 2D row by row scanning strategy. This is an important contribution because the 2D row by row scanning is extremely fast and easy to implement unlike the fringe following scanning. We have called this method the phase curvature tracker (PCT) because it uses the frequency curvature as regularizer to obtain the expected phase as a C^2 function with continuous curvature.