2018, Perez-Cortes, Juan-Carlos, Pérez Jiménez, Alberto José, Sáez Barona, Sergio, Guardiola Garcia, Jose Luis, Salvador Igual, Ismael, Instituto Universitario Mixto de Tecnología de Informática, Departamento de Informática de Sistemas y Computadores, Escuela Técnica Superior de Ingeniería Informática, Institut Valencià de Competitivitat Empresarial, European Regional Development Fund

[EN] This work presents a 3D scanner able to reconstruct a complete object without occlusions, including its surface appearance. The technique presents a number of differences in relation to current scanners: it does not require mechanical handling like robot arms or spinning plates, it is free of occlusions since the scanned part is not resting on any surface and, unlike stereo-based methods, the object does not need to have visual singularities on its surface. This system, among other applications, allows its integration in production lines that require the inspection of a large volume of parts or products, especially if there is an important variability of the objects to be inspected, since there is no mechanical manipulation. The scanner consists of a variable number of industrial quality cameras conveniently distributed so that they can capture all the surfaces of the object without any blind spot. The object is dropped through the common visual field of all the cameras, so no surface or tool occludes the views that are captured simultaneously when the part is in the center of the visible volume. A carving procedure that uses the silhouettes segmented from each image gives rise to a volumetric representation and, by means of isosurface generation techniques, to a 3D model. These techniques have certain limitations on the reconstruction of object regions with particular geometric configurations. Estimating the inherent maximum error in each area is important to bound the precision of the reconstruction. A number of experiments are presented reporting the differences between ideal and reconstructed objects in the system.

2020-12, Pérez Jiménez, Alberto José, Pérez Cortés, Juan Carlos, Guardiola Garcia, Jose Luis, Instituto Universitario Mixto de Tecnología de Informática, Departamento de Informática de Sistemas y Computadores, Escuela Técnica Superior de Ingeniería Informática

[EN] A precise calibration in multi-view camera environments allows to perform accurate 3D object reconstruction, precise tracking of objects and accurate pose estimation. Those techniques are of high value in the industry today in fields as quality control or automation. In the present work, an improvement of a simple existing multi-view camera calibration method is presented. The improved method employs a specially developed reference token to overcome some issues in the original algorithm. We prove that the new method overcomes those problems thus attaining a higher accuracy while keeping the process simple and the implementation costs low. This last aspects makes the method interesting for the industry but specially suitable for SMEs typical in traditional sectors.