RT Journal Article T1 Two-step interferometry by a regularized optical flow algorithm A1 Quiroga Mellado, Juan Antonio A1 Vargas Balbuena, Javier A1 Sánchez Sorzano, Carlos Óscar A1 Estrada, Julio César A1 Carazo García, José María AB A two-step phase-shifting method, that can demodulate open-and closed-fringed patterns without local sign ambiguity is presented. The proposed method only requires a constant phase-shift between the two interferograms. This phase-shift does not need to be known and can take any value inside the range (0, 2 π), excluding the singular case where it corresponds to π. The proposed method is based on determining first the fringe direction map by a regularized optical flow algorithm. After that, we apply the spiral phase transform (SPT) to one of the fringe patterns and we determine its quadrature signal using the previously determined direction. The proposed technique has been applied to simulated and experimental interferograms obtaining satisfactory results. A complete MATLAB software package is provided in [http://goo.gl/Snnz7]. PB The Optical Society Of America SN 0146-9592 YR 2011 FD 2011-09-01 LK https://hdl.handle.net/20.500.14352/43912 UL https://hdl.handle.net/20.500.14352/43912 LA eng NO 1. D. Malacara and M. Servín, and Z. Malacara, Interferogram Analysis for Optical Testing (Marcel Dekker, Inc, 1998).2. M. Servín, J. C. Estrada, and J. A. Quiroga, Opt. Express 17, 21867 (2009).3. M. Takeda, H. Ina, and S. Kobayashi, J. Opt. Soc. Am. 72 156 (1982).4. T. M. Kreis and W. P. O. Jueptner, Proc. SPIE 1553, 263 (1992).5. J. Vargas, J. A. Quiroga, T. Belenguer, M. Servín, and J. C. Estrada, Opt. Express 19, 638 (2011).6. B. K. P. Horn and B. G. Schunck, Artif. Intell. 17, 185 (1981).7. K. G. Larkin, D. J. Bone, and M. A. Oldfield, J. Opt. Soc. Am. A 18, 1862 (2001).8. J. A. Quiroga and M. Servín, Opt. Commun. 224, 221 (2003).9. Z. Y. Wang and B. T. Han, Opt. Lett. 29, 1671 (2004).10. http://goo.gl/Snnz7. NO © 2011 Optical Society of America.We would like to acknowledge partial support from theSpanish Ministry of Science and Innovation throughgrants ACI2009-1022, ACI2010-108 and BIO2010-16566. NO Spanish Ministry of Science and Innovation DS Docta Complutense RD 26 ago 2024