Enlarging computer-vision sensing-capabilities using pseudo-periodic patterns on the target of interest Patrick Sandoz 1 , Maxime Jacquot 1 , Val´ erian Guelpa 1 , July A. Galeano Zea 2 , Miguel Asmad Vergara 1,3 , C´ edric Cl´ evy 1 , Guillaume J. Laurent 1 1 FEMTO-ST Institute, Universit´ e Bourgogne Franche-Comt´ e, CNRS, 15B avenue des Montboucons, 25030 Besanc ¸on, France 2 Grupo de Investigacin en Materiales Avanzados y Energ´ ıa MatyEr, L´ ınea Biomateriales y Electromedicina, Instituto Tecnol´ ogico Metropolitano, ITM, Medell´ ın 050013, Colombia 3 Secci´ on F´ ısica, Departamento de Ciencias, Pontificia Universidad Cat´ olica del Per´ u, Apartado 1761, Lima, Peru patrick.sandoz@univ-fcomte.fr Abstract: Using pseudo-periodic patterns on the observed target releases usual computer- vision constraints by allowing subpixelic resolutions together with supra field-of-observation absolute measurement ranges. The allowed range of working distances is also tremendously extended using digital holography. OCIS codes: 120.0120, 150.0150, 150.5670, 090.1995, 070.0070. 1. Improved visual sensors using pseudo-periodic patterns on the target of interest Computer vision is a powerful contact-less measurement tools successfully applied in numerous domains of appli- cation. In classical configurations however, optimal trade-offs have to be fund between resolution - that improves with higher magnifications - and measurement range - that is tied to the field of observation and increases with lower magnifications. Depth of field and working distances are also constrained by the imaging magnification chosen. The use of pseudo-periodic patterns on the target of interest releases these usual computer-vision limitations in two main ways: i) The periodic pattern character allows phase measurements leading to subpixelic resolutions thanks to data averaging and efficient noise rejection. ii) Finely designed alterations of the periodic frame allows unambiguous pattern position encryption that makes the absolute measurement range independent of the field-of-observation of the imaging system [1]. Range-to-resolution ratios of about 10 6 were demonstrated with standard imaging devices [2]. Fig. 1. Left: Free oscillations of a compliant structure measured versus a single direction at 1989fps. Middle: 2D pattern for displacement measurements in 2D. Right: Same trajectory reconstructed by digital holography at working distances separated by more than 15cm. This approach was successfully applied to position registration [3], in-plane displacement measurements [2, 4] and micro-force measurements [5]. The approach was also validated using digital holography as imaging method with a tremendous enlargement of the allowed working distance range [6]. This paper presents an overview of this