Computer-Assisted Assembling of Fragmented Objects

Si propone un medoto semi automatico ed interattivo per la ricostruzione virtuale di oggetti frammentati. Tramite un'interfaccia, l'utente specica un insieme di constraints tra coppie di frammenti ( digitalizzati come mesh di triangoli) o tra gruppi di frammenti. Il metodo ~A stato testato con successo su un inseme di casi reali

An optimizational approach for an algorithmic reassembly of fragmented objects

In Cambodia close to the Thai border, lies the Angkor-style temple of Banteay Chhmar. Like all nearly forgotten temples in remote places, it crumbles under the ages. By today most of it is only a heap of stones. Manually reconstructing these temples is both complex and challenging: The conservation team is confronted with a pile of stones, the original position of which is generally unkown. This reassembly task resembles a large-scale 3D puzzle. Usually, it is resolved by a team of specialists who analyze each stone, using their experience and knowledge of Khmer culture. Possible solutions are tried and retried and the stones are placed in different locations until the correct one is found. The major drawbacks of this technique are: First, since the stones are moved continuously they are further damaged, second, there is a threat to the safety of the workers due to handling very heavy weights, and third because of the high complexity and labour-intensity of the work it takes several months up to several years to solve even a small part of the puzzle. These risks and conditions motivated the development of a virtual approach to reassemble the stones, as computer algorithms are theoretically capable of enumerating all potential solutions in less time, thereby drastically reducing the amount of work required for handling the stones. Furthermore the virtual approach has the potential to reduce the on-site costs of in-situ analysis. The basis for this virtual puzzle algorithm are high-resolution 3D models of more than one hundred stones. The stones can be viewed as polytopes with approximately cuboidal form although some of them contain additional indentations. Exploiting these and related geometric features and using a priori knowledge of the orientation of each stone speeds up the process of matching the stones. The aim of the current thesis is to solve this complex large-scale virtual 3D puzzle. In order to achieve this, a general workflow is developed which involves 1) to simplify the high-resolution models to their most characteristic features, 2) apply an advanced similarity analysis and 3) to match best combinations as well as 4) validate the results. The simplification step is necessary to be able to quickly match potential side-surfaces. It introduces the new concept of a minimal volume box (MVB) designed to closely and storage efficiently resemble Khmer stones.Additionally, this reduced edge-based model is used to segment the high-resolution data according to each side-surface. The second step presents a novel technique allowing to conduct a similarity analysis of virtual temple stones. It is based on several geometric distance functions which determine the relatedness of a potential match and is capable of sorting out unlikely ones. The third step employs graph theoretical methods to combine the similarity values into a correct solution of this large-scale 3D puzzle. The validation demonstrates the high quality and robustness of this newly constructed puzzle workflow. The workflow this thesis presents virtually puzzles digitized stones of fallen straight Khmer temple walls. It is able to virtually and correctly reasemble up to 42 digitized stones requiring a minimum of user-interaction

Computer aided puzzle assembly based on shape and texture information /

Puzzle assembly’s importance lies into application in many areas such as restoration and reconstruction of archeological findings, the repairing of broken objects, solving of the jigsaw type puzzles, molecular docking problem, etc. Puzzle pieces usually include not only geometrical shape information but also visual information of texture, color, continuity of lines, and so on. Moreover, textural information is mainly used to assembly pieces in some cases, such as classic jigsaw puzzles. This research presents a new approach in that pictorial assembly, in contrast to previous curve matching methods, uses texture information as well as geometric shape. The assembly in this study is performed using textural features and geometrical constraints. First, the texture of a band outside the border of pieces is predicted by inpainting and texture synthesis methods. The feature values are derived by these original and predicted images of pieces. A combination of the feature and confidence values is used to generate an affinity measure of corresponding pieces. Two new algorithms using Fourier based image registration techniques are developed to optimize the affinity. The algorithms for inpainting, affinity and Fourier based assembly are explained with experimental results on real and artificial data. The main contributions of this research are: The development of a performance measure that indicates the level of success of assembly of pieces based on textural features and geometrical shape. Solution of the assembly problem by using of the Fourier based methods

Report on shape analysis and matching and on semantic matching

In GRAVITATE, two disparate specialities will come together in one working platform for the archaeologist: the fields of shape analysis, and of metadata search. These fields are relatively disjoint at the moment, and the research and development challenge of GRAVITATE is precisely to merge them for our chosen tasks. As shown in chapter 7 the small amount of literature that already attempts join 3D geometry and semantics is not related to the cultural heritage domain. Therefore, after the project is done, there should be a clear ‘before-GRAVITATE’ and ‘after-GRAVITATE’ split in how these two aspects of a cultural heritage artefact are treated.This state of the art report (SOTA) is ‘before-GRAVITATE’. Shape analysis and metadata description are described separately, as currently in the literature and we end the report with common recommendations in chapter 8 on possible or plausible cross-connections that suggest themselves. These considerations will be refined for the Roadmap for Research deliverable.Within the project, a jargon is developing in which ‘geometry’ stands for the physical properties of an artefact (not only its shape, but also its colour and material) and ‘metadata’ is used as a general shorthand for the semantic description of the provenance, location, ownership, classification, use etc. of the artefact. As we proceed in the project, we will find a need to refine those broad divisions, and find intermediate classes (such as a semantic description of certain colour patterns), but for now the terminology is convenient – not least because it highlights the interesting area where both aspects meet.On the ‘geometry’ side, the GRAVITATE partners are UVA, Technion, CNR/IMATI; on the metadata side, IT Innovation, British Museum and Cyprus Institute; the latter two of course also playing the role of internal users, and representatives of the Cultural Heritage (CH) data and target user’s group. CNR/IMATI’s experience in shape analysis and similarity will be an important bridge between the two worlds for geometry and metadata. The authorship and styles of this SOTA reflect these specialisms: the first part (chapters 3 and 4) purely by the geometry partners (mostly IMATI and UVA), the second part (chapters 5 and 6) by the metadata partners, especially IT Innovation while the joint overview on 3D geometry and semantics is mainly by IT Innovation and IMATI. The common section on Perspectives was written with the contribution of all

Urban Heritage Planning in Tehran and Beyond: Sequences of Disrupted Spatial-Discursive Assemblages

Despite the impact of ideological rigidity, the primary challenge of heritage planning in Tehran and beyond lies not in the dominance of an inflexible Authorized Heritage Discourse, but rather in the absence of stable spatial-discursive and administrative structures. Solmaz Yadollahi maps the historical trajectory of conservation and urban heritage planning in Iran, depicting a discursive-spatial assemblage that tends to knock down its accumulated resources. This is in line with Katouzian's portrayal of Iran as a pick-axe society. Residing within this society, the studied assemblage strives to deconstruct the prevailing structures and usher in a fresh one, paradoxically perpetuating the very cycle it seeks to escape

Scattered Finds: Archaeology, Egyptology and Museums

Between the 1880s and 1980s, British excavations at locations across Egypt resulted in the discovery of hundreds of thousands of ancient objects that were subsequently sent to some 350 institutions worldwide. These finds included unique discoveries at iconic sites such as the tombs of ancient Egypt's first rulers at Abydos, Akhenaten and Nefertiti’s city of Tell el-Amarna and rich Roman Era burials in the Fayum. Scattered Finds explores the politics, personalities and social histories that linked fieldwork in Egypt with the varied organizations around the world that received finds. Case studies range from Victorian municipal museums and women’s suffrage campaigns in the UK, to the development of some of the USA’s largest institutions, and from university museums in Japan to new institutions in post-independence Ghana. By juxtaposing a diversity of sites for the reception of Egyptian cultural heritage over the period of a century, Alice Stevenson presents new ideas about the development of archaeology, museums and the construction of Egyptian heritage. She also addresses the legacy of these practices, raises questions about the nature of the authority over such heritage today, and argues for a stronger ethical commitment to its stewardship

What does climate change change? Understanding climate change in the work of heritage government authorities in England and Sweden

This thesis critically examines the impact of climate change on the heritage work of Historic England (HE) and the Riksantikvarieämbetet (‘Swedish National Heritage Board’ – RAÄ). The research is based on the understanding of climate change as a hyperobject (Morton, 2013), a term coined to describe the ways in which climate change does not only operate through its physical impact but also shifts social and material relations between humans, nonhumans and inanimate agents. By applying an ethnographic methodology, this thesis critically reflects on the responses of HE and the RAÄ to the climate crisis by questioning what understandings of climate change and heritage inform these and, subsequently, what this means for climate action and the creation of (alternative) futures. The research develops around three themes representing both organisations' primary climate change engagements: adaptation, mitigation, and participation. The thesis argues that the first two responses are informed by understanding climate change as an environmental impact and a carbon problem. The third theme considers how both organisations aim to be included in the climate change discourse as it takes place in other sectors, particularly in the natural environment sector and how they attempt to challenge these existing nature/culture dichotomies. However, I will argue that they do not overcome this dualism on the ontological level. Throughout, it argues that both organisations uphold an anthropocentric approach that aims to demonstrate heritage's relevance and positive impact by emphasising the benefits of its conservation to its human custodians, while climate change remains framed as an external impact. The latter prevents a critical reflection of the existing heritage discourse, the socio-environmental and political drivers of the climate crisis and the role heritage plays in these. Therefore, in conclusion, this thesis briefly reflects on what role heritage could play in futures that challenge the current status quo

A Relational Account of Structure and Agency via ‘Lived Ancient Religion’ and the ‘Processing Approach,’ with a Case Study of Circumcision in Ancient Judaism

Addressing studies of the concepts of structure and agency, in 2008 sociologist François Dépelteau called for a ‘relational approach’ that compared the ‘trans-actions’ of actors, but notably left open the question of how such a study should be conducted. The present article attempts to operationalise Dépelteau’s call, albeit in a manner tailored specifically to meet the needs of researchers in the area of ‘lived ancient religion’. The study of ‘trans-action’ is operationalised here by employing key terms drawn from Staf Hellemans’s ‘processing approach’ to the study of religion, in which agents ‘process’ their environments through selection, modification, assembly, performance, integration, and resonance. In the study of the religions of Mediterranean antiquity, questions of structure and agency can be addressed relationally by comparing the performances of specific actors, to the extent that such performances are accessible in the material evidence; for example, in the form of texts, statuary, art, and architecture. In an attempt to demonstrate the utility of this approach, a case study of the ritual of circumcision in ancient Judaism is offered

Museum Digitisations and Emerging Curatorial Agencies Online

This open access book explores the multiple forms of curatorial agencies that develop when museum collection digitisations, narratives and new research findings circulate online. Focusing on Viking Age objects, it tracks the effects of antagonistic debates on discussion forums and the consequences of search engines, personalisation, and machine learning on American-based online platforms. Furthermore, it considers eco-systemic processes comprising computation, rare-earth minerals, electrical currents and data centres and cables as novel forms of curatorial actions. Thus, it explores curatorial agency as social constructivist, semiotic, algorithmic, and material. This book is of interest to scholars and students in the fields of museum studies, cultural heritage and media studies. It also appeals to museum practitioners concerned with curatorial innovation at the intersection of humanist interpretations and new materialist and more-than-human frameworks