A 3D scanner for transparent glass

Many practical tasks in industry, such as automatic inspection or robot vision, often require the scanning of three-dimensional shapes by use of non-contact techniques. However, few methods have been proposed to measure three-dimensional shapes of transparent objects because of the difficulty of dealing with transparency and specularity of the surface. This paper presents a 3D scanner for transparent glass objects based on Scanning From Heating (SFH), a new method that makes use of local surface heating and thermal imaging

Scanning from heating: 3D shape estimation of transparent objects from local surface heating

Today, with quality becoming increasingly important, each product requires three-dimensional in-line quality control. On the other hand, the 3D reconstruction of transparent objects is a very difficult problem in computer vision due to transparency and specularity of the surface. This paper proposes a new method, called Scanning From Heating (SFH), to determine the surface shape of transparent objects using laser surface heating and thermal imaging. Furthermore, the application to transparent glass is discussed and results on different surface shapes are presented

Close range mini Uavs photogrammetry for architecture survey

The survey of historical façades contains several bottlenecks, mainly related to the geometrical structure, the decorative framework, the presence of natural or artificial obstacles, the environment limitations. Urban context presents additional restrictions, binding by ground acquisition activity and leading to building data loss. The integration of TLS and close-range photogrammetry allows to go over such stuff, not overcoming the shadows effect due to the ground point of view. In the last year the massive use of UAVs in survey activity has permitted to enlarge survey capabilities, reaching a deeper knowledge in the architecture analysis. In the meanwhile, several behaviour rules have been introduced in different countries, regulating the UAVs use in different field, strongly restricting their application in urban areas. Recently very small and light platforms have been presented, which can partially overcome these rules restrictions, opening to very interesting future scenarios. This article presents the application of one of these very small RPAS (less than 300 g), equipped with a low-cost camera, in a close range photogrammetric survey of an historical building façade in Bologna (Italy). The suggested analysis tries to point out the system accuracy and details acquisition capacity. The final aim of the paper is to validate the application of this new platform in an architectonic survey pipeline, widening the future application of close-range photogrammetry in the architecture acquisition process

Iterative partitioning and labelling of point cloud data

Over the past few years the acquisition of 3D point information representing the structure of real-world objects has become common practice in many areas. This acquisition process has traditionally been carried out using 3D scanning devices based on laser or structured light techniques. Professional grade 3D scanners are nowadays capable of producing highly accurate data at sampling rates of approximately a million points per second. Moreover the popularisation of algorithms and tools capable of generating relatively accurate virtual representations of real-world scenes from photographs without the need of expensive and specialised hardware has led to an increase in the amount and availability of 3D point cloud data. The management and processing of these huge volumes of scanned data is quickly becoming a problem.peer-reviewe

Structured light in the digital reconstruction of architectural details

[EN] The interest in cataloguing historical heritage has involved the growing development of techniques of three-dimensional scanning in recent years. The present work introduces the technique of structured light as a digitalization method that despite its limitations provides a powerful tool for surveying architectural details. The results found with structured light in the architectural survey of the Hospital Real of the Universidad de Granada (Spain) have been satisfactory as a substitute or a complement to the laser scanner and digital photography.[ES] El interés en la catalogación del patrimonio histórico ha supuesto un creciente desarrollo de las técnicas de escaneado en tres dimensiones en los últimos años. En el presente trabajo se introduce la técnica de luz estructurada como un método de digitalización que, a pesar de sus limitaciones, es una potente herramienta para el levantamiento de detalles arquitectónicos. Los resultados obtenidos con la luz estructurada en el levantamiento arquitectónico del Hospital Real de la Universidad de Granada han sido satisfactorios como sustitutivo o complemento al escáner láser y la fotogrametría digital.León Robles, C.; Reinoso Gordo, JF.; Mataix Sanjuán, J. (2018). Luz estructurada en la reconstrucción digital de detalles arquitectónicos. EGA. Revista de Expresión Gráfica Arquitectónica. 23(32):198-207. doi:10.4995/ega.2018.9810SWORD198207233

3D scanning of cultural heritage with consumer depth cameras

Three dimensional reconstruction of cultural heritage objects is an expensive and time-consuming process. Recent consumer real-time depth acquisition devices, like Microsoft Kinect, allow very fast and simple acquisition of 3D views. However 3D scanning with such devices is a challenging task due to the limited accuracy and reliability of the acquired data. This paper introduces a 3D reconstruction pipeline suited to use consumer depth cameras as hand-held scanners for cultural heritage objects. Several new contributions have been made to achieve this result. They include an ad-hoc filtering scheme that exploits the model of the error on the acquired data and a novel algorithm for the extraction of salient points exploiting both depth and color data. Then the salient points are used within a modified version of the ICP algorithm that exploits both geometry and color distances to precisely align the views even when geometry information is not sufficient to constrain the registration. The proposed method, although applicable to generic scenes, has been tuned to the acquisition of sculptures and in this connection its performance is rather interesting as the experimental results indicate

A multiscale feature extraction approach for 3D range images

This paper presents a multiscale feature extraction technique for 3D range images. Optimized and improved 3D Gaussian filtering and saliency map computation have been conceived jointly to the exploitation of connectivity relationships naturally induced by the 2D acquisition grid. The proposed algorithmic and implementation solutions guarantee good repeatability of detected features on different views and demonstrated superior computational performance compared to other known approaches

FEM Model an Effective Tool to Evaluate Von Mises Stresses in Shoulder Joint and Muscles for Adduction and Abduction

AbstractShoulder is one of the most complicated and critical joint. It consists of the clavicle, scapula and humerus. Studying individual functions of these structures is nearly unfeasible. In order to understand these relationships during different shoulder exercise, an attempt has been made to model, simulate and analyze the shoulder joint.The technique described in this paper utilizes the advanced 3D scanning; Computer Aided Design (CAD), DMU Kinematics Tool in CATIA V5 then Finite Element Analysis (FEA) to detect the stress points of the shoulder joints during adduction and abduction. FEM of the ligaments and the muscles are carried out using the hexa-penta mesh elements in Hyper Mesh and von mises stresses are analysed by LS DYNA software. The results for abduction and adduction are plotted and validated with the previous research papers as well as the limiting values of the different shoulder muscle for the range of motion 0° to 30°

Construction, Management and Visualization of 3D Models of Large Archeological and Architectural Sites for E-Heritage GIS Systems

In this paper we present an integrated system developed in order to record, construct, pre-process, manage, visualize and visually navigate 3D models reality based of large archeological and architectural sites for eHeritage GIS systems. The framework integrates structured geometrical and documentary information resulting from multiple sources with the aim to enhance the knowledge of those sites within the frame of its historical evolution and its institutional management in a 3D GIS/DB. The developed applications were designed for different types of users, with a largely scalable interface, able to support different output devices and to work at different levels of iconicity. The system allows a full comprehension of the buildings in their own context, permitting to discover unknown relationships, to evaluate their architectural occupancy and to quickly access a complex system of information. The framework has been tested in two different systems - designed and developed to satisfy both internal (cataloguing, documentation, preservation, management of archaeological heritage) and external (communication through the web portal) purposes: the first, in Pompeii, developed in order to have a web-based system that uses Open Source software and complies with national and international standards; the second one, a prototype designed to make available on the Google Earth platform the complete Palladian corpus documentation implemented by the CISAAP