Quiroga Mellado, Juan AntonioGonzález Cano, Agustín2023-06-202023-06-202000-030957-023310.1088/0957-0233/11/3/313https://hdl.handle.net/20.500.14352/58790© 2000 IOP Publishing Ltd. We wish to acknowledge the support of a post-doctoral grant from the Universidad Complutense de Madrid, the ‘Becas Internacionales Flores-Valles’ program, Spain, and the Centro de Investigaciones en Óptica (CIO), León, México. This work has been partially supported by the project TAP 98-0701/97 of the CICyT (Comisión Interministerial de Ciencia y Tecnología).We present a method for automatic determination of isostatics from the photoelastic measurement of isoclinics obtained by phase-shifting techniques. The method is based on the integration of two difference equations by use of a multigrid algorithm, using a quality map obtained from experimental data by checking the consistency of the generated experimental differences. So-called isostatic sulfaces are determined and, from them, the isostatics net can be drawn with any prescribed density and resolution. The algorithm is very robust and fast and has proven very efficient for working with real photoelastic fringe patterns.engjournal articlehttp://dx.doi.org/10.1088/0957-0233/11/3/313http://iopscience.iop.orgopen access535PhotoelasticityIsostaticsPhase ShiftingMultigridFringe-Pattern AnalysisÓptica (Física)2209.19 Óptica Física