Edited by Anna Bentkowska-Kafel and Orla Murphy
Colour and Space in Cultural Heritage (COSCH) is an interdisciplinary network of experts in and users of the latest optical measuring techniques and imaging applied to documentation of artefacts. COSCH aims to enhance the existing practice and standards in 3D documentation, by promoting a better understanding of science and widening the use of specialist technologies. COSCH networking activities are funded by COST, an intergovernmental framework for European Cooperation in Science and Technology, allowing the coordination of nationally-funded research on a European level. COSCH is a COST Transdomain Action in the area of Materials, Physics and Nanosciences. Funding has been made available from 2012 to 2016.
Anna Bentkowska-Kafel, Eryk Bunsch, Amandine Colson, Bogdan Constantinescu, Christian Degrigny, José Ignacio Murillo Fragero, Julien Guery, Eleni Kouloumpi, Miroslav Hain, Florent Laroche, Rafael Martín Talaverano, Natasa Michailidou, Orla Murphy, Sérgio Nascimento, Roberto Padoan, Antonio Pelegrina, Mieke Pfarr-Harfst, Marcello Picollo, Christine Riquier-Bouclet, Stefan Röhrs, Robert Sitnik, Despoina Tsiafakis, Tatiana Vitorino, Stefanie Wefers >>>
The current issue of the COSCH e-Bulletin reports on the activities of the five working groups constituting the COST Action, ‘Colour and Space in Cultural Heritage', in the period from November 2014 to July 2015. Interim results are presented of the Action's ongoing work towards a conceptual, scientific, technical and procedural consensus in defining best documentation standards and recording practice — of using a range of spatial and spectral optical technologies, in particular electronic metrology, imaging and 3/4D visualisation. >>>
COSCH Profile: Mieke Pfarr-Harfst
An interview with Mieke Pfarr-Harfst of Darmstadt Technical University >>>
COSCH Interim Reports 2012–14
These interim reports cover the activities of the Working Groups of "Colour and Space in Cultural Heritage" (www.cosch.info), the COST Transdomain Action TD1201, supported by the European Cooperation in Science and Technology between 2012– 2016.
- Preface by Frank Boochs
The report covers the period from 2012 to 2014. Spectral imaging techniques have been increasingly applied to the study and documentation of cultural heritage objects in the past years, and a large number of sophisticated and varied instruments has been made available. The activities of COSCH WG1 focus on the identification, characterisation and testing of 2D multi- and hyper-spectral imaging techniques in the Vis-NIR-SWIR regions, and beyond, in this context. Concerning the many difficulties with accessing, processing and comparing the data obtained with different imaging devices, the group is working towards the development of standardised methodologies and most efficient practices regarding the application of these techniques in the art conservation field, taking in consideration the needs of various cultural heritage end-users. The present interim report introduces the purposes and development of spectral imaging techniques in the field, and the reasons for gaining a better understanding of spectroscopic instruments and the elements of data acquisition; it also proposes to define terminology. The report presents the round robin test developed by the working group, which has focussed on typical cultural heritage objects and questions commonly posed in the art conservation field. This test aims to explore and compare characteristics and performances of spectral imaging devices and approaches developed by different research groups, and to understand their impact on data accuracy. The final version of the report will shed light on the challenges and difficulties faced by end-users, and ensure the usefulness, reliability and comparability of the data from different instruments and institutions. >>>
COSCH Working Group 2: Spatial Object Documentation (PDF), by Robert Sitnik and Miroslav Hain
The report covers the period from 2012 to 2014. The WG2, Spatial Object Documentation, is focusing on two main tasks: identification of the main 3D scanning techniques suitable for cultural heritage (CH) objects; analysis and comparison of different 3D scanning techniques. An overview is provided of the main existing techniques in terms of their practical usage, accuracy and availability. This discussion is illustrated by practical results of comparison of measurements of small fragments of a 17th-century ceramic stove tile with floral decoration in high relief. The main drawback of existing solutions is their limited capacity to measure the variety of surface properties of CH objects, most of which have a complex, composite structure. Further, an overview of multimodal CH objects representation is presented. To achieve this goal two main approaches are developed: software- and hardware-based data measurement and integration. The members of WG2 conclude that future technologies will be based on multimodal and/or modular measurement systems with the adaptive data processing platform (as proposed by the COSCH WG3). Existing technologies only allow for measurement of one modality at a time, and by a particular system or device. There are some solutions for multimodal measurements. However, they are still not mature enough to be used in everyday 3D measurement practice. >>>
- COSCH Working Group 3: Algorithms and Procedures (PDF) by Alain Trémeau and Orla Murphy
The report covers the period from 2012 to 2014. The ubiquity of algorithms embedded in everyday life for many who use technology has not, yet, allowed the non-expert users of systems any insight into their function and use. The work of this targeted workgroup seeks to assess, formalise and explain the range of algorithms in use in systems within cultural heritage. Certainly at times for the non-expert user of certain applications it is not apparent what algorithm is being used, and most importantly why it is being used. This paper aims to introduce a range of algorithms currently used in cultural heritage acquisition and measurement systems, offering explanations, and looking to develop recommendations and guidelines for use, depending on minimal spatial resolution and uncertainty values specified amongst a range of considerations; to inform users of the potential, output, constraints, preconditions and practical aspects related to the use of algorithms and procedures used to process digital data (both spectral and spatial data) and most importantly to structure knowledge about algorithms and procedures used in DCH in an ontology laying a foundation for an optimised and adapted use of algorithms and procedures for processing digital data by cultural heritage professionals. >>>
The report covers the period from 2012 to 2014. In this period, WG4 carried out a critical review of typical applications of spatial and spectral imaging techniques to the conservation field, to assess the potential constraints and preconditions imposed by such techniques, as well as evaluate the results and analyse the added value of their combined usage. The field covered being huge, the multidisciplinary team of experts concentrated their efforts on a few materials (mainly metals, works on paper and paintings). They were particularly interested in checking whether the techniques considered responded to the needs, comparing the performance of one imaging technique to another, and assessing how the characteristics of each material were affecting the acquisition of data.
Although essential, the point of view of the end-user is rarely put forward. Therefore the present assessment focused on a few techniques considered by conservation professionals to be easy to use and low cost. One of them is Highlight-Reflectance Transformation Imaging (H-RTI), which is particularly suitable for flat objects with some reliefs (coins, engravings, mural decorations, etc.). The map obtained is composed of multiple photographs taken from one stationary position, while the surface of the object is illuminated in each shot from different raking light positions. Interactively re-lit, the object reveals surface detail. Online software facilitates the exchange of data between end-users. >>>
The report covers the period from 2012 to 2014. Three-dimensional visualisation is a result of complex interactions between researchers and editors, science and technology specialists, with resources, the project background and contexts, and diverse working processes. Among the important issues that arise in this field are the high cost and access to the technical expertise and instruments needed to incorporate this technology in traditional Cultural Heritage (CH) research, the lack of automation and consistent standards, the huge amount of data produced, their variety (3D models, geographical data, metadata, paradata etc.), as well as their efficient and effective management, especially in terms of sustainability and long-term archiving. These restrictions are particularly acute within museums and other CH institutions, while the lack of appropriate principles and methods of documentation neither assures quality in relation to a scholarly content, nor use of knowledge contained in these 3D models for future generations.
The purpose of this report is to identify similarities and differences of typical working processes and methodologies in the field of 3D modelling of CH. Based on this we define general phases of a process and strategies in the methodology, as well as a definition of CH visualisation typology. The report offers recommendations for further work within the COSCH network and development of guidelines for scientific and CH researchers, and general public, that will assist them in 3D visualisation of cultural heritage. >>>
News from the Field
3D Recording, Documentation and Management of Cultural Heritage, a new book by Efstratios Stylianidis and Fabio Remondino, forthcoming from Whittles Publishing. >>>
Contents: Introduction current trends in cultural heritage and documentation; Conservation techniques in cultural heritage; Cultural heritage management tools: The role of GIS and BIM; Basics of photography for cultural heritage imaging; Basics of image-based modelling techniques in cultural heritage 3D recording; Basics of range-based modelling techniques in cultural heritage 3D recording; Cultural heritage documentation with RPAS/UAV.
I think this should be essential reading for everyone in COSCH! Lindsay MacDonald
- 3D Survey of the 7-century BC Tombs at Otzing, Deggendorf in Lower Bavaria. Animation and commentary by Tobias Reich and Robert Schumann. >>>
The Contributors gratefully acknowledge the support of the European Cooperation in Science and Technology, the COST Action TD1201 "Colour and Space in Cultural Heritage" (www.cosch.info).
The Interim Reports on the activities of COSCH Working Groups have been peer-reviewed. Reviewers' comments were communicated to the Authors and helped to revise and enhance the reports.
The articles in this issue express the views of the authors and not necessarily those of the COSCH Editorial Board and reviewers.
© Colour and Space in Cultural Heritage. Reports © individual author(s) and reproduction is with their permission. Illustrations © individual authors and photographers.