High-Resolution Imaged-Based 3D Reconstruction Combined with X-Ray CT Data Enables Comprehensive Non-Destructive Documentation and Targeted Research of Astromaterials

Providing web-based data of complex and sensitive astromaterials (including meteorites and lunar samples) in novel formats enhances existing preliminary examination data on these samples and supports targeted sample requests and analyses. We have developed and tested a rigorous protocol for collecting highly detailed imagery of meteorites and complex lunar samples in non-contaminating environments. These data are reduced to create interactive 3D models of the samples. We intend to provide these data as they are acquired on NASA's Astromaterials Acquisition and Curation website at http://curator.jsc.nasa.gov/

THE DIAGNOSIS OF ROAD SURFACE DISTRESSES THROUGH IMAGE-BASED MODELING TECHNIQUES. EXPERIMENTAL SURVEY ON LABORATORY-RUTTED SAMPLES

In the past few years, there has been a drastic increase in the use of image-based modeling (IBM) techniques to create high quality, reality-based 3D models. The low costs of these techniques, as well as their attractive visual quality, have led many researchers and professionals to invest their energy and resources in several tests. IBM is rarely used in the field of road surface distresses as diagnosis is usually performed using other techniques and devices. Road safety statistics reveal that about a half of the total number of accidents occur mainly due to the deterioration of the pavement. The goal of effective road network management is often incompatible with economic resources designated for maintenance and rehabilitation. For this reason, IBM diagnosis of distresses seems necessary in order to both increase the level of road safety and to avoid incorrect interventions and treatments of road pavement. One of the strengthens of multi-view stereo techniques is the possibility to capture millions of points in a very short time, and to produce a 3D, textured polygonal model that can easily be used for visualizing and communicating digital assets. Our goal was to implement the IBM techniques on a laboratory-rutted sample and to verify the metric accuracy of the model and its validity for the distress diagnosis in terms of severity (rut depth). In order to assess the IBM technique, we compared its 3D model to the blue LED 3D scan (Artec Spider) of the same rutted sample

PROJECT “TOWARDS THE VIRTUAL MUSEUM” – EXPLORING TOOLS AND METHODS FOR 3D DIGITALIZATION AND VISUALIZATION

A 3-year pilot project “Towards the Virtual Museum – 3D-digitalization of A-category objects selected from the collection of Archaeological Museum in Zagreb” has a primary objective to enhance the accessibility of museum collection to a bigger audience, both scientific and the general public. The project goal is to research existing tools and methods for 3D digitalization and visualization of archaeological objects different in size and material. Digital models achieved by 3D scanning techniques will be equally used for virtual reconstruction, making replicas, scientific analysis and detailed damage recordings on ob- jects and monuments

Heritage and technology: novel approaches to 3D documentation and communication of architectural heritage

In the past few years we have seen a drastic increasing of image-based modeling (IBM) techniques to get high quality reality-based 3D models. The low costs of these techniques as well as their attractive visual quality have lead many researchers and professionals to invest their energies and resources in several tests. The use of IMB in the field of cultural heritage is mostly exploited in applications such as documentation, digital restoration, visualization, inspection, planning, AR/VR, conservation and design. One of the strengthen of multi-view stereo techniques is the possibility to capture millions of points in a very short time and to get a 3D textured polygonal model that can be easily used for visualizing and communicating digital assets. Currently, we can distinguish between desktop and web based packages. If the first one needs a high performance computer for data processing, the second one use the power of cloud computing to carry out a semi-automatic data processing instead of considerably slowing-down the computer. The aim of this study is to compare two of the most known IBM packages (Agisoft Photoscan and Autodesk Recap) in applications dealing with architectural heritage. The comparison among the chosen packages are typical user-oriented parameters such as: visual completeness/detail of the 3D model; ratio between images resolution/number of images/time processing; number of used/discharged images (useful to optimize the images network); metric accuracy; learning curve/usability

IMAGE-BASED MODELING TECHNIQUES FOR ARCHITECTURAL HERITAGE 3D DIGITALIZATION: LIMITS AND POTENTIALITIES

3D reconstruction from images has undergone a revolution in the last few years. Computer vision techniques use photographs from data set collection to rapidly build detailed 3D models. The simultaneous applications of different algorithms (MVS), the different techniques of image matching, feature extracting and mesh optimization are inside an active field of research in computer vision. The results are promising: the obtained models are beginning to challenge the precision of laser-based reconstructions. Among all the possibilities we can mainly distinguish desktop and web-based packages. Those last ones offer the opportunity to exploit the power of cloud computing in order to carry out a semi-automatic data processing, thus allowing the user to fulfill other tasks on its computer; whereas desktop systems employ too much processing time and hard heavy approaches. Computer vision researchers have explored many applications to verify the visual accuracy of 3D model but the approaches to verify metric accuracy are few and no one is on Autodesk 123D Catch applied on Architectural Heritage Documentation. Our approach to this challenging problem is to compare the 3Dmodels by Autodesk 123D Catch and 3D models by terrestrial LIDAR considering different object size, from the detail (capitals, moldings, bases) to large scale buildings for practitioner purpose

The survey of the Basilica di Collemaggio in L’Aquila with a system of terrestrial imaging and most proven techniques

The proposed job concerns the evaluation of a series of surveys carried out in the context of a campaign of studies begun in 2015 with the objective of comparing the accuracies obtainable with the systems of terrestrial imaging, compared to unmanned aerial vehicle imaging and laser scanner survey. In particular, the authors want to test the applicability of a system of imaging rover (IR), an innovative terrestrial imaging system, that consists of a multi-camera with integrated global positioning system (GPS)/global navigation satellite system (GNSS) receiver, that is very recently released technique, and only a few literature references exist on the specific subject. In detail, the IR consists of a total of 12 calibrated cameras – seven “panorama” and five downward-looking – providing complete site documentation that can potentially be used to make photogrammetric measurements. The data acquired in this experimentation were then elaborated with various software packages in order to obtain point clouds and a three-dimensional model in different cases, and a comparison of the various results obtained was carried out. Following, the case study of the Basilica di Santa Maria di Collemaggio in L’Aquila is reported; Collemaggio is an UNESCO world heritage site; it was damaged during the seismic event of 2009, and its restoration is still in progress

3D MODELLING AND INTERACTIVE WEB-BASED VISUALIZATION OF CULTURAL HERITAGE OBJECTS

Nowadays, there are rapid developments in the fields of photogrammetry, laser scanning, computer vision and robotics, together aiming to provide highly accurate 3D data that is useful for various applications. In recent years, various LiDAR and image-based techniques have been investigated for 3D modelling because of their opportunities for fast and accurate model generation. For cultural heritage preservation and the representation of objects that are important for tourism and their interactive visualization, 3D models are highly effective and intuitive for present-day users who have stringent requirements and high expectations. Depending on the complexity of the objects for the specific case, various technological methods can be applied. The selected objects in this particular research are located in Bulgaria – a country with thousands of years of history and cultural heritage dating back to ancient civilizations. \this motivates the preservation, visualisation and recreation of undoubtedly valuable historical and architectural objects and places, which has always been a serious challenge for specialists in the field of cultural heritage. In the present research, comparative analyses regarding principles and technological processes needed for 3D modelling and visualization are presented. The recent problems, efforts and developments in interactive representation of precious objects and places in Bulgaria are presented. Three technologies based on real projects are described: (1) image-based modelling using a non-metric hand-held camera; (2) 3D visualization based on spherical panoramic images; (3) and 3D geometric and photorealistic modelling based on architectural CAD drawings. Their suitability for web-based visualization are demonstrated and compared. Moreover the possibilities for integration with additional information such as interactive maps, satellite imagery, sound, video and specific information for the objects are described. This comparative study discusses the advantages and disadvantages of these three approaches and their integration in multiple domains, such as web-based 3D city modelling, tourism and architectural 3D visualization. It was concluded that image-based modelling and panoramic visualisation are simple, fast and effective techniques suitable for simultaneous virtual representation of many objects. However, additional measurements or CAD information will be beneficial for obtaining higher accuracy

TLS MODELS GENERATION ASSISTED BY UAV SURVEY

By now the documentation and 3D modelling activities of built heritage concern in an almost usual way terrestrial Lidar techniques (TLS, Terrestrial Laser Scanning), and large scale mapping derived by UAV (Unmanned Aerial Vehicle) survey. This paper refers an example of 3D survey and reality based modelling applied on landscape and architectural assets. The choice of methods for documentation, in terms of survey techniques, depends primarily on issues and features of the area. The achieved experience, allow to consider that the easy handling of TLS has enabled the use in limited spaces among buildings and collapsed roofs, but the topographic measure of GCPs (Ground Control Points), neither by total station nor by GPS/RTK technique, was easily feasible. Even more than proving the ability of the integration of TLS and UAV photogrammetry to achieve a multi-source and multi-scale whole model of a village, the experience has been a test to experiment the registration of terrestrial clouds with the support of control points derived by UAV survey and finally, a comparison among different strategies of clouds registration is reported. Analysing for each approach a number of parameters (number of clouds registration, number of needed points, processing time, overall accuracy) the further comparisons have been achieved. The test revealed that it is possible to decrease the large number of terrestrial control points when their determination by topographical measures is difficult, and it is possible to combine the techniques not only for the integration of the final 3Dmodel, but also to solve and make the initial stage of the drafting process more effective

New Opportunities in Digital Archaeology: The Use of Low-Cost Photogrammetry for 3D Documentation of Archaeological Objects from Banks Island, NWT

This thesis investigates the use of low-cost three-dimensional (3D) modelling programs (Agisoft Photoscan and 123D Catch) to create and disseminate digital replicas of archaeological features and artifacts in the context of the Ikaahuk Archaeology Project, a community-based archaeology project on Banks Island, Northwest Territories. It aims to 1) assess the benefits and challenges of low-cost photogrammetry for in-situ documentation of hunter-gatherer archaeological features; 2) determine the usefulness of low-cost photogrammetry for replicating small-scale artifacts in comparison to 3D scanning methods; and 3) explore how Internet media can be used to disseminate 3D models. This thesis demonstrates that low-cost methods of 3D modelling are sufficiently able to replicate many types of archaeological objects, and are accessible due to their low cost, ease of use, and compatibility with online dissemination. As a result low-cost 3D modelling has a promising future in archaeological documentation, conservation, and engagement with non-specialist audiences