Évaluation métrologique d'algorithmes de corrélation d'images numériques
Résumé
Optical full field measurement techniques based on digital image correlation get more and more popular. We propose a methodology for the assessment of the metrological performances of the image processing algorithms that constitute their central component, the knowledge of which is required for a global assessment of the whole measurement system. It is based on the generation of synthetic images representative of real speckle patterns, deformed according to a sinusoidal displacement field with varying amplitude and period, and the statistical analysis of the discrepancies between imposed and measured values. It has been applied to various softwares used in the french community. Results show general tendencies rather independent from the implementations but strongly correlated with the assumptions of the underlying algorithms. Various error regimes are identified, for which the dependence of the accuracy with the parameters of the algorithms, such as correlation window size or shape functions can be precised.
Origine : Fichiers produits par l'(les) auteur(s)