Modélisation 3D d'objets par un capteur visuel déplacé par un opérateur

The work of this thesis focuses on modeling 3D objects from small to medium sized (1m3 maximum) with an innovative sensor moved manually by an operator, developed by theNOOMEOTM company.To acquire 3D data, the sensor consists of a camera system coupled with an illuminator. Weinfer information from a a visual pattern projected on the scene, used to create the artificialtexture on 3D surface, to produce a 3D image of the scene. Surfaces are represented as 3Dpoints reconstructed from the current viewpoint. To completely model an object, the sensormust be moved around the object to acquire several 3D images. These images are successivelyregistered and merged into a single 3D point cloud. A triangular mesh is then generated fromthe 3D point cloud. The appearance (color and texture) of the object can also be extractedfrom data acquisition to enrich the final model.This thesis addresses the problem of registration of 3D views in two ways : the fast onlineregistration and offline accurate optimization. For the first approach we proposed a variant ofthe ICP algorithm using information from images and inertial measurement. This method wasvalidated by comparing it to other common geometric registration methods. For the secondapproach, we proposed a refinment strategy by minimization of cycles in a graph of relationsbetween the 3D views ; and a global pose optimization method.Our methods and their integration into a complete modeling system were validated bycomparing our results with those from other scanning systems commonly used in scientificand industrial communities.Les travaux de cette thèse portent sur la modélisation 3D d’objets de petite et moyenne tailles(1 m3 maximum) par un système innovant, développé par la société NOOMEOTM, déplacémanuellement par un opérateur.Pour acquérir les données 3D, le capteur est constitué d’un système de caméras couplé à unilluminateur. La projection sur la scène d’un motif visuel permet de créer sur les surfaces3D une texture artificielle exploitée pour produire une image 3D de la scène, soit l’ensemblede points 3D reconstruits depuis le point de vue courant. Pour obtenir le modèle completd’un objet, le capteur doit être déplacé autour de l’objet afin d’acquérir plusieurs images3D. Ces images sont successivement recalées et fusionnées dans un seul nuage de points 3D.Un maillage triangulaire est ensuite généré à partir de ce nuage de points 3D. L’apparence(couleur et texture) de l’objet peut également être extraite des données d’acquisition afind’enrichir le modèle final.Cette thèse aborde le problème du recalage de vues 3D selon deux approches : le recalagerapide en ligne et l’optimisation précise hors ligne. La première approche nous a conduit àproposer une variante de la méthode ICP exploitant l’information des images et la mesureinertielle. Cette méthode a été validée en la comparant à d’autres méthodes courantes derecalage géométrique. Pour la seconde approche, nous avons proposé une stratégie de raffinageexploitant la minimisation de cycles dans un graphe de relations entre les vues 3D ; puis uneméthode d’optimisation globale des poses.Nos méthodes et leur intégration dans le système de modélisation complet ont été validésen comparant nos résultats avec ceux d’autres systèmes de numérisation couramment utilisésdans les communautés scientifique et industrielle

Registration Strategies of 3D Images Acquired From a Hand-held Visual Sensor

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Pose Interpolation for Rolling Shutter Cameras using Non Uniformly Time-Sampled B-splines

International audienceRolling Shutter (RS) cameras are predominant in the tablet and smartphone market due to their low cost and small size. However, these cameras require specific geometric models when either the camera or the scene is in motion to account for the sequential exposure of the different lines of the image. This paper proposes to improve a state-of-the-art model for RS cameras through the use of Non Uniformly Time-Sampled B-splines. This allows to interpolate the pose of the camera taking into account the varying dynamic of the motion by adding more control points where needed while keeping a low number of control points where the motion is smooth. Two methods are proposed to determine adequate distributions for the control points, using either an IMU sensor or an iterative reprojection error minimization. Results on simple synthetic data sets are shown to prove the concept and future works are introduced that should lead to the integration of our model in a SLAM algorithm

An innovative hand-held vision-based digitizing system for 3D modelling

International audienceWe describe a new hand-held 3D modelling device using vision and inertialmeasurements. Our system allows fast and accurate acquisition of the ge-ometry and appearance information of any 3D object. We focused our worktowards an easy manipulation and operating condition.Our methods allow automatic registration with no preparation of thescene (i.e. no markers) even when the object is moved between two acquisitions.In this paper, the design of the system and the developed methods for itsuse are presented. The system has been evaluated, qualitatively and quan-titatively, using reference measurements provided by commercial scanningdevices. The results show that this new hand-held scanning device is reallycompetitive for modelling any 3D object

Precise Registration of 3D Images Acquired from a Hand-Held Visual Sensor

13th International Conference on Advanced Concepts for Intelligent Vision Systems (ACIVS) / 5th ACM/IEEE International Conference on Distributed Smart Cameras (ICDSC), Ghent Univ, Ghent, BELGIUM, AUG 22-25, 2011International audienceThis paper presents a method for precise registration of 3D images acquired from a new sensor for 3D digitization moved manually by an operator around an object. The system is equipped with visual and inertial devices and with a speckle pattern projector. The presented method has been developed to address the problem that a moving speckle pattern during a sequence prevents from correlating points between images acquired from two successive viewpoints. So several solutions are proposed, based on images acquired with a moving speckle pattern. It improves ICP-based methods classically used for precise registration of two clouds of 3D points

Modélisation 3D d'objets par un capteur visuel déplacé par un opérateur

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Radiometric confidence criterion for patch-based inpainting

International audienceDiminished Reality (DR) consists in virtually removing objects from a captured scene, thus requiring a coherent filling of the areas originally hidden behind these objects. Indoor DR applications often exploit the planar geometry of the scene to apply an inpainting process on a perspectively undistorted view of the plane. In this paper we propose to integrate a novel, physic-based criterion into classical state-of-the-art inpainting algorithms in order to take into account the variations in image resolution of the undistorted view. The proposed inpainting process selects the patches and avoids the propagation of low-resolution data, i.e. patches corresponding to parts of the plane that are far from the camera or seen under an very skew angle. We illustrate the improvements of DR results on synthetic and real images

Shape measurement using a new 3D-DIC algorithm that preserves sharp edges

International audienc

Radiometric confidence criterion for patch-based inpainting

International audienceDiminished Reality (DR) consists in virtually removing objects from a captured scene, thus requiring a coherent filling of the areas originally hidden behind these objects. Indoor DR applications often exploit the planar geometry of the scene to apply an inpainting process on a perspectively undistorted view of the plane. In this paper we propose to integrate a novel, physic-based criterion into classical state-of-the-art inpainting algorithms in order to take into account the variations in image resolution of the undistorted view. The proposed inpainting process selects the patches and avoids the propagation of low-resolution data, i.e. patches corresponding to parts of the plane that are far from the camera or seen under an very skew angle. We illustrate the improvements of DR results on synthetic and real images

Shape measurement using a new 3D-DIC algorithm that preserves sharp edges

International audienc