Calibration of RGB camera with velodyne LiDAR

Calibration of the LiDAR sensor with RGB camera finds its usage in many application fields from enhancing image classification to the environment perception and mapping. This paper presents a pipeline for mutual pose and orientation estimation of the mentioned sensors using a coarse to fine approach. Previously published methods use multiple views of a known chessboard marker for computing the calibration parameters, or they are limited to the calibration of the sensors with a small mutual displacement only. Our approach presents a novel 3D marker for coarse calibration which can be robustly detected in both the camera image and the LiDAR scan. It also requires only a single pair of camera-LiDAR frames for estimating large sensors displacement. Consequent refinement step searches for more accurate calibration in small subspace of calibration parameters. The paper also presents a novel way for evaluation of the calibration precision using projection error

SURVEY PLANNING FOR DOCUMENTATION OF A MONUMENT FOR THE UNDERSTANDING, PRESERVATION AND RESTORATION

The three-dimensional (3D) preservation and repair of historic sites are increasingly in practice using modelling and digital documentation. This study focuses on replacing conventional techniques of historical documentation by creating a digital documentation procedure employing laser scanning for 3D mapping of a monument located in Prayagraj, India. To quickly record the entire monument structure, four scanning stations were planned, where three for the facades and one for the interior. A 3D structure of the monument and its elements dimension that included structural, architectural, historical, and non-engineering information was the end product. Researchers, architects, and conservationists can use this laser scanning-based technique to analyze data in great detail to identify weaknesses and conservation requirements. In order to preserve the monument's cultural relevance, it can also be used for virtual tours. Digital documentation can also provide an accurate monument record for restoration needs, protecting the monument from human- or natural-caused damage. Overall, 3D Modelling and digital documentation are valuable tools in heritage conservation, providing comprehensive records of heritage sites and aiding in practical conservation and restoration plans while making cultural heritage accessible to a broader societies

Virtual tourism – Digital scanning, Augmented Reality and Virtual Reality as a Holistic Approach to Chinese Historic Building Preservation

There are many historical buildings spread around the rural areas of China and very few of them have been documented through digital media. In the face of massive Chinese urbanization, many of these cultural relics are facing the risk of damage, collapse, and even disappearance. The undocumented disappearance of these monuments would be a great loss for Chinese traditional culture and therefore this thesis proposes to solve this preservation problem using a combination of digital media platforms including 3D digital reconstruction, virtual reality, and augmented reality to digitally document and present these monuments. This thesis introduces these three technologies individually by presenting case studies for each to illustrate in greater depth the value each technology brings into the realm of heritage conservation. In the final section of this thesis, a mixed reality educational mobile application is presented as a test of this integrated technology solution to explore the potential of implementing this solution on a massive scale

Virtual Heritage

Virtual heritage has been explained as virtual reality applied to cultural heritage, but this definition only scratches the surface of the fascinating applications, tools and challenges of this fast-changing interdisciplinary field. This book provides an accessible but concise edited coverage of the main topics, tools and issues in virtual heritage. Leading international scholars have provided chapters to explain current issues in accuracy and precision; challenges in adopting advanced animation techniques; shows how archaeological learning can be developed in Minecraft; they propose mixed reality is conceptual rather than just technical; they explore how useful Linked Open Data can be for art history; explain how accessible photogrammetry can be but also ethical and practical issues for applying at scale; provide insight into how to provide interaction in museums involving the wider public; and describe issues in evaluating virtual heritage projects not often addressed even in scholarly papers. The book will be of particular interest to students and scholars in museum studies, digital archaeology, heritage studies, architectural history and modelling, virtual environments

Virtual Heritage

Virtual heritage has been explained as virtual reality applied to cultural heritage, but this definition only scratches the surface of the fascinating applications, tools and challenges of this fast-changing interdisciplinary field. This book provides an accessible but concise edited coverage of the main topics, tools and issues in virtual heritage. Leading international scholars have provided chapters to explain current issues in accuracy and precision; challenges in adopting advanced animation techniques; shows how archaeological learning can be developed in Minecraft; they propose mixed reality is conceptual rather than just technical; they explore how useful Linked Open Data can be for art history; explain how accessible photogrammetry can be but also ethical and practical issues for applying at scale; provide insight into how to provide interaction in museums involving the wider public; and describe issues in evaluating virtual heritage projects not often addressed even in scholarly papers. The book will be of particular interest to students and scholars in museum studies, digital archaeology, heritage studies, architectural history and modelling, virtual environments

Reconstruçao 3D de acervos culturais usando câmeras RGB-D : solução de compromisso entre precisão e tempo aplicada ao projeto Aleijadinho Digital

Orientador : Olga Regina Pereira BellonCoorientador : Luciano SilvaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Informática. Defesa: Curitiba, 29/04/2016Inclui referências : f. 67-78Área de concentração : Ciência da computaçãoResumo: Neste trabalho é proposto a utilização de câmeras RGB-D dentro do contexto de digitalização 3D de acervos culturais. O grupo de pesquisa no qual este trabalho foi desenvolvido está atuando no projeto Aleijadinho Digital. Este projeto consiste da digitalização do acervo deixado pelo artista barroco Aleijadinho. Uma das contribuições desta tese está na apresentação de um estudo comparativo sobre os projetos mais relevantes da área da preservação digital. As diversas tecnologias de geração 3D destes e outros projetos de preservação cultural também são discutidas e classificadas. Os scanners tradicionalmente utilizados nestes trabalhos possuem alta precisão, chegando na casa dos micrômetros. No entanto podem custar até centenas de milhares de dólares, necessitam de tripés, fonte própria de energia, treinamento para calibrar e operar o equipamento, espaço físico amplo e a aquisição pode durar alguns minutos para uma única captura. Enquanto os sensores RGB-D apesar da menor precisão realizam até 60 capturas por segundo, são simples de serem operados, necessitam apenas da conexão com um notebook e em geral custam até 100 dólares. Diversos trabalhos recentes apresentaram métodos que exploram o potencial destes sensores. No entanto, estas abordagens com frequência apresentam deformações quando aplicadas em reconstruções 3D completas, 360 graus, para diversos objetos. Neste trabalho é proposto uma metodologia completa de reconstrução 3D baseada em câmeras RGB-D. E para atenuar o efeito da deformação é apresentado um método de alinhamento baseado em pares que expande o grafo de conectividade. Isto é feito através de um método original para detecção automática de novos pares de malhas 3D com região de sobreposição. Esta medida permite que eventuais erros de alinhamento sejam distribuídos de forma mais homogênea entre um maior número de pares de alinhamento. Esta técnica de alinhamento é importante pois o acúmulo de erro é intensificado pela grande quantidade de imagens geradas por câmeras RGBD. Os experimentos foram realizados utilizando os dados de 30 obras do projeto Aleijadinho Digital, realizado em parceria com a UNESCO. Com o auxílio de modelos criados com um sensor 3D de precisão submilimétrica específico para tarefa de reconstrução 3D, experimentos comparativos foram realizados contra outros métodos estado da arte. Os resultados apresentados foram favoráveis ao método proposto no que diz respeito a precisão geométrica. Palavras-chave: kinect, alinhamento, reconstrução 3D, acervos culturais.Abstract: This work proposes a 3D reconstruction method using RGB-D cameras within the context of 3D digital preservation of cultural heritage. Our research group is involved in Digital Aleijadinho project, which consists of the digitization of the artworks from this baroque artist. We present a comparative study of the most influential projects of the digital preservation area, their contributions and 3D generation technologies. Scanners traditionally used in these projects can achieve micrometer precision. However they also can cost up to hundreds of thousands of dollars, require tripods, own source of energy, training to calibrate and operate the equipment, ample space and the acquisition may take several minutes for a single capture. While the RGB-D sensors despite the lower precision they achieve up to 60 fps, they are easy to operate, requiring only the connection to a notebook and generally cost up to $100. Several recent studies presented methods that exploit the potential of these sensors. However, these approaches often exhibit errors when applied to full 3D reconstruction of di_erent objects, known as the loop closure problem. This work proposes a complete methodology of 3D reconstruction based on RGB-D cameras.And to mitigate the loop closure e_ect we present an pairwise alignment method that expands the graph connectivity.This is done through a new method that expands connections in a pairwise alignment system by automatically discovering new pairs of meshes with overlapping region. Then the alignment error is distributed more evenly over the aligned pairs avoiding the loop closure of full 3D reconstructions. Our alignment approach is necessary because the error accumulation is intensified by the large amount of data generated by RGB-D cameras. The experiments were performed using the data of 30 artworks of Digital Aleijadinho project, conducted in partnership with UNESCO. Our experiments show detailed 3D models and favorably compare with state-of-the-art methods found in literature. Keywords: kinect, alignment, 3D reconstruction, cultural heritage

3D Information Technologies in Cultural Heritage Preservation and Popularisation

This Special Issue of the journal Applied Sciences presents recent advances and developments in the use of digital 3D technologies to protect and preserve cultural heritage. While most of the articles focus on aspects of 3D scanning, modeling, and presenting in VR of cultural heritage objects from buildings to small artifacts and clothing, part of the issue is devoted to 3D sound utilization in the cultural heritage field

3D Recording and Interpretation for Maritime Archaeology

This open access peer-reviewed volume was inspired by the UNESCO UNITWIN Network for Underwater Archaeology International Workshop held at Flinders University, Adelaide, Australia in November 2016. Content is based on, but not limited to, the work presented at the workshop which was dedicated to 3D recording and interpretation for maritime archaeology. The volume consists of contributions from leading international experts as well as up-and-coming early career researchers from around the globe. The content of the book includes recording and analysis of maritime archaeology through emerging technologies, including both practical and theoretical contributions. Topics include photogrammetric recording, laser scanning, marine geophysical 3D survey techniques, virtual reality, 3D modelling and reconstruction, data integration and Geographic Information Systems. The principal incentive for this publication is the ongoing rapid shift in the methodologies of maritime archaeology within recent years and a marked increase in the use of 3D and digital approaches. This convergence of digital technologies such as underwater photography and photogrammetry, 3D sonar, 3D virtual reality, and 3D printing has highlighted a pressing need for these new methodologies to be considered together, both in terms of defining the state-of-the-art and for consideration of future directions. As a scholarly publication, the audience for the book includes students and researchers, as well as professionals working in various aspects of archaeology, heritage management, education, museums, and public policy. It will be of special interest to those working in the field of coastal cultural resource management and underwater archaeology but will also be of broader interest to anyone interested in archaeology and to those in other disciplines who are now engaging with 3D recording and visualization

Remote Sensing and Geosciences for Archaeology

This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications