REFLECTANCE IMAGING FOR CULTURAL HERITAGE
Heritage libraries, museums, archives, and documentary collections are containers of historical information. How are centuries-old books and state-of-the-art digital imaging coming together on research platforms? New developments in scientific imaging for assessing the characteristics of fragile medieval documents and books are becoming a productive source of historical evidence, revealing data invisible to the human eye. The methods of work of medieval scribes, illuminators and print makers now being revealed form a fascinating topic for historians and a vital source for cultural studies and the developing field of heritage study and conservation.
The RICH project (Reflectance Imaging for Cultural Heritage, Illuminare, Centre for the Study of Medieval Art, KU Leuven, in collaboration with ESAT) is developing an imaging tool for research, study, and exploration of the material characteristics of graphic materials produced in medieval and early modern times. With the minidome, the topography of medieval book illuminations, stamps, inks, seals and bookbinding stamps is visualized and monitored in 3D.
The hemispherical shaped imaging device digitizes with multi-directional lighting. The technique is based on polynomial texture mapping, also known as Reflectance Transformation Imaging (RTI), a technique of imaging and interactively displaying objects under varying lighting conditions to reveal surface phenomena. The module has 260 LED-lamps evenly spread across the inside of the hemisphere and a single downward looking video camera (28 million pixels). The object to be captured is positioned in the center and, throughout the capture, is illuminated by the subsequent activation of individual white LEDs. After capture, the 260 images are mapped and processed. Through virtual relighting, fine details can be highlighted by the use of specific digital filters, bringing out structures that are not visible under single illumination. The different angles of light that illuminate the artifact reveal minute details. Fine measurements and height profiles can be generated through the application and exported to 3D.
The development of the RICH minidome will enable multi-spectral imaging, is expanding non-destructive art-technical research and has great potential as an instrument in determining conservation treatments of irreplaceable cultural heritage artifacts.
The advantage of the qualitative and accurate results of the RICH mini-dome visualization is found in the multiple ways they can be handled and used. They are all based on one and the same recording, taking a few minutes. A large number of visualization filters and relighting options can be applied to the virtual images; they permit the recognition of difficult accessible surfaces of these objects, 2D+ models can be generated, allowing actual interaction with the recorded artifact. There is an online interactive web viewer for all results of the Portable mini Dome recordings that can be downloaded.
Project team & contact:
For more information please visit The RICH project blog.Promotor: Prof. J. Van der Stock Copromotors: CS Digital (Prof. F. Truyen), University Library (Prof. S. Gradmann), ESAT (Prof. L. Van Gool) External Partner: Museum Plantin Moretus (Unesco World Heritage) The RICH project is funded by the Hercules Foundation
Upcoming Lectures and Conferences
Lieve Watteeuw en Bruno Vandermeulen, "See the Surface. Imaging and measuring surface characteristics of library materials by photometric stereo ( RICH Project)", Digital Humanities@Arts Summer School, Leuven, 8 September 2014.
Lieve Watteeuw, Bruno Vandermeulen & Jan Van der Stock, "Technical Session: The RICH Project", Technical Studies of paintings: problems of attribution (15th-17th century), XIXth symposium for the Study of Underdrawing and Technology in Painting, Bruges, 11-13 September 2014.
Lieve Watteeuw, "Imaging the Topography of Illuminations and Bookbindings with the Minidome (RICH). A 2D+ imaging tool for Art-technical and Conservation Monitoring", ICOM-CC, 17th Triennial Conference, Melbourne, Australia, 15-19 September 2014.
Past Lectures and Conferences
June 6 2014, Leuven, Workshop RICH, Reflectance Imaging for Cultural Heritage, Workshop in context of the conference 'Inside Illuminations', organized by Illuminare
June 5-6 2014, Brussels, Inside Illuminations, Art Technical Research & the Illuminated Manuscript, Conference organized by KIK-IRPA, Illuminare and UCL
May 28-31 2014, San Francisco, AIC Conference (American Association for Conservation), Conscientious Conservation – Sustainable Choices in Collection Care, Book & Paper Group (click here for a report by Henry Hebert on the RICH project presentation)
January 29, 2014, Barcelona (Spain), EuropeanaPhotography seminar on software for managing image collections, "DAM in the context of research; the case of RICH"
December 17, 2013, Ghent, FWO, Kennismakers, AL 85 jaar zuurstof voor Onderzoek en Ontwikkeling, KU Leuven, Gent, ICC
August 15-16, 2013, Washington DC (USA), Folger Shakespeare Library, New Bownde: New Scholarship in Early Modern Binding, Digital Rubbings: "Imaging the topography of Bookbinding Stamps with the Minidome (RICH)". Workshop and lecture.
Objects monitored with RICH ( 2012 – 2013) are from the following collections
KU Leuven, University Library & Tabularium (Collection of Manuscripts, Prints & Bookbindings)
KU Leuven, Maurits Sabbe Library (Collection of Manuscripts & Bookbindings)
KU Leuven, University Archives (Charters & Seals) UNESCO Heritage
Antwerp, Museum Plantin-Moretus (Collection of Illuminated Manuscripts) UNESCOHeritage
Antwerp, Museum Mayer van den Bergh (Mss, Evangeliarium van Sawalo, 12th century)
Antwerp, Rubenshuis, Theoretical Notebook of P.P. Rubens (Mss., Bordes Codex, 17th century)
Antwerp, Kerkfabriek St. Willibrord ( Mss., Missal of Berchem, 12th century)
Nijvel (Nivelles), Musée de la Ville (Cuir Bouilli fragment, Flanders, 1400)
Washington, Folger Schakespeare Library (Collection of Leather & Textile Bookbindings)
Imaging Characteristics of Graphic Materials with the Minidome (RICH)
Source: ICOM-CC Graphic Documents Working Group Interim Meeting | Vienna 17 – 19 April 2013
Lieve Watteeuw | Bruno Vandermeulen | Jan Van der Stock | Pierre Delsaerdt |
Stefan Gradmann | Fred Truyen | Marc Proesmans | Wim Moreau | Luc Van Gool
KU Leuven, Faculty of Arts; Illuminare, University Library & ESAT-Visics,
Department of Electrical Engineering, Leuven, Belgium
The RICH project
RICH (Reflectance Imaging for Cultural Heritage, KU Leuven, 2012-2015) is creating a digital imaging tool for researching, studying, and exploring material characteristics of library materials. In 2005, the first generation of the module was created for reading cuneiform tablets in the department of Assyriology of the University of Leuven (KU Leuven). With the second generation of the imaging devise, developed in 2013, the visualization of paper and parchment artifacts, paper and wax seals, illumination and bookbinding stamps (gold- and blind tooled, on the back and on the boards of bindings) is in development. The imaging tool can create a sharp and exact image of the surface in 2D+ and proofs to be an accurate documentation tool for monitoring surface characteristics of graphic materials.
Fig. 1: Dome for digitizing with omnimulti-directional lighting and export the result to 2D+. (© ESAT, KU Leuven)
Fig. 2: Last folio of a severely damaged 19th century manuscript on paper, imaged with raking light and adding a shade filter. (© RICH, KU Leuven)
The digital imaging device, IMROD (Imaging Module for Multi-spectral, Reflectance or 2D+), is digitizing with omnimulti-directional lighting and exports the result to 2D+ (Fig. 1). The technique is based on polynomial texture mapping, also known as Reflectance Transformation Imaging (RTI), a technique of imaging and interactively displaying objects under varying lighting conditions to reveal surface phenomena. The module is a hemi-spherical structure with a single downward looking video camera (28 million pixels). The object to be captured (maximum 180 to 120 mm) lies in the center and is illuminated from computer-controllable lighting directions, through the subsequent activation of multiple white LEDs. The different angles that illuminate the surface of the artifacts are revealing extreme details. Special attention is taken to produce raking light to provide information on the surface topography. For each illumination an image is taken by the overhead camera, in total 264 images for each object. After processing these 264
images, filters in the visualization system like virtual lighting, shading and sketch are incorporated in the software. The application of these filters allows detailed documentation of surface characteristics, irregularities, undulations, flaking, lacunas and the different levels of loss of the pictorial layers of the researched artifact. After capturing the images, fine details can be highlighted by the use of specific digital filters, bringing out structures that would be less visible under single illumination (like shade, contrast, sharpening and sketch filters) (Fig. 2 - 4). The tool is portable and mobile which makes it possible to examine books and archives in situ.