Quiroga Mellado, Juan AntonioServín Guirado, ManuelEstrada, Julio CésarGómez Pedrero, José Antonio2023-06-202023-06-202009-04-200003-693510.1364/AO.48.002401https://hdl.handle.net/20.500.14352/43978© 2009 Optical Society of America. We thank the Ministerio de Ciencia y Tecnología of Spain for the financial support of this work given by project DPI2005-03891. Also M. Servin and J. C. Estrada acknowledge the financial support of the Mexican Consejo Nacional de Ciencia y Tecnología (CONACYT).It is well known that spatial phase shifting interferometry (SPSI) may be used to demodulate two-dimensional (2D) spatial-carrier-interfrograms. In these crises the application of SPSI is straightforward because the modulating phase is a monotonic increasing function of space. However, this is not true when we apply SPSI to demodulate a single-image interferogram containing closed fringes. This is because using these algorithms, one would obtain a wrongly demodulated monotonic phase all over the 2D space. We present a technique to overcome this drawback and to allow any SPSI algorithm to be used as a single-image fringe pattern demodulator containing closed fringes. We make use of the 2D spatial orientation direction of the fringes to steer (orient) the one-dimensional SPSI algorithm in order to correctly demodulate the nonmonotonic 2D phase all over the interferogram.engjournal articlehttp://dx.doi.org/10.1364/AO.48.002401http://www.opticsinfobase.orgopen access535Transform ProfilometryQuadrature TransformPattern DemodulationFourier-TransformAlgorithmInterferometryOrientationCarrierÓptica (Física)2209.19 Óptica Física