[EN] 3D object alignment is essential in multiple fields. For instance, to allow precise measurements in metrology, to perform surface/volumetric checks or quality control in industrial inspection, to align partial captures of a 3D object during object scanning, to simplify object recognition or classification in pattern recognition, accuracy and speed, being opposed, are desirable features of those algorithms. Nevertheless, they can be more or less critical depending on the application area. In the present work, we propose a methodology to improve the alignment of 3D objects reconstructed using shape-from-silhouette techniques. This reconstruction technique produces objects with small synthetic bulges, making them more difficult to align accurately. On the one hand, prealignment and branch-and-bound techniques are used to improve the convergence and speed of the alignment algorithms. On the other hand, a method to obtain a precise alignment even in the presence of bulges is presented. Finally, a refinement of the shape-from-silhouettes technique is shown. This technique uses multiple captures to refine object reconstruction and reduce or eliminate, among other improvements, synthetic bulges.

This work was supported in part by European Union Horizon Europe Programme Artificial Intelligence Driven Industrial Equipment Product Life Cycle Boosting Agility, Sustainability and Resilience (AIDEAS) under Grant 101057294; and in part by the Generalitat Valenciana through Instituto Valenciano de Competitividad Empresarial [Valencian Institute of Business Competitiveness (IVACE)] Distributed Nominatively to Valencian Technological Innovation Centres under Project IMAMCA/2023/11.