Search results for "3d scanning"
showing 5 items of 15 documents
3D shape extraction of internal and external surfaces of glass objects
2013
Three-dimensional (3D) digitization of manufactured objects has been investigated for several years and consequently, many techniques have been proposed. Even if some techniques have been successfully commercialized, most of them assume a diffuse or near diffuse reflectance of the object’s surface, and difficulties remain for the acquisition of “optically non cooperative” surfaces, such as transparent or specular ones. To address such surfaces, we propose a non conventional technique, called “Scanning from Heating” (SfH). In contrast to classical active triangulation techniques that acquire the reflection of visible light, we measure the thermal emission of the heated surface. The aim of th…
Preprocessing of region of interest localization based on local surface curvature analysis for three-dimensional reconstruction with multiresolution
2009
We present an approach to integrate a preprocessing step of the region of interest ROI localization into 3-D scanners laser or ste- reoscopic. The definite objective is to make the 3-D scanner intelligent enough to localize rapidly in the scene, during the preprocessing phase, the regions with high surface curvature, so that precise scanning will be done only in these regions instead of in the whole scene. In this way, the scanning time can be largely reduced, and the results contain only per- tinent data. To test its feasibility and efficiency, we simulated the prepro- cessing process under an active stereoscopic system composed of two cameras and a video projector. The ROI localization is…
Automation of Acquisition and Post-processing for 3D Digitalisation
2009
The automation of digitalisation is an indispensable step in the development of 3D measuring, in various fields :- in industry, to accelerate the procedures for control of parts,- in archaeology and biology, for the study of collections of several hundreds even thousand objects (for which the acquisition is for the moment impossible because of necessary time, and thus of the cost). In this thesis, we explain first the various existing systems of acquisition and positioning, by detailing the advantages and the inconveniences of every system. We present then the developed methodology to guide the operator in these choices as well as the tool set up to formalize this methodology. Then we will …
THE SCENOGRAPHY OF SERPOTTA STUCCOES REVISITED - MATERIAL AND FORM
2015
The material that lies beneath the smooth shining surface of the stuccoes of the Serpotta family who used to work in Sicily from 1670 to 1730, has been thoroughly studied in previous papers, disclosing the deep, albeit empirical, knowledge of materials science that guided the artists in creating their masterpieces. In this work, attention is focused on the solid perspective and on the scenographic sculpture by Giacomo Serpotta, who is acknowledged as the leading exponent of the School. The study deals with some particular works of the artist, the “small-scaled plastic theatres”, so-called “teatrini”, which he made for the San Lorenzo Oratory in Palermo. On the basis of archival documents an…
New Data on the Silver Objects from the House of Eupolemos (Morgantina, Sicily)
2015
Due to their intrinsic value, ancient silver objects have often arrived at museums throughout the world with provenance other than that of regular excavations, and therefore much data regarding the context and the production process in the workshops of origin, as well as the circulation of such objects, is missing. The discovery of silver objects, in fact, is derived from what one may define as non-productive hoarding – archaeological collections created through the formal burial or the furtive hiding in a moment of danger of objects that were never recovered – circumstances that limit the possibility of knowing the primary use of the object in antiquity, in the manner that we can determine…