Imaging Characteristics of Graphic Materials with the Minidome (RICH)

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. The digital imaging device, IMROD (Imaging Module for Multi-spectral, Reflectance or 2D+) is digitizing with omnimulti-directional lighting and export the result to 2D+( Illustration 1). The technique is based on polynomial texture mapping / 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 provides 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 de 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 less visible under single illumination ( like shade, contrast, sharpening and sketch filters). Until 2015 the RICH project will develop further this tool for researching and understanding the material and tactile characteristics of graphic materials. Examination and identification of the production of graphic objects, changes in their structures (the supports) and pictorial layers (paint, inks, drawing- and printing materials, varnish, gilding, retouching, abrasion) proved to be an extremely accurate documentation tool during the first stage of the project. Complementary, RICH is useful to monitor the conservation and preservation status of an object before and after treatment, transport or exhibition. The results will be managed and disseminated through a portal and image database (2014-2015).The Interim Meeting of the Working Group Graphic Documents will be held in Vienna from 17 to 19 April 2013, hosted by the Austrian National Library. The two-day conference will provide a forum for the broad spectrum of activities in the Paper Conservation community. Challenges of digitization, changing cultural policies and economic constraints on one hand, current research and advancements in materials and techniques on the other hand demand growing competences of paper-, library-, and archive conservators. To which extent are decision processes in conservation influenced by changes in ethics, politics and science? Do conservators have the profile to shape these processes and to negotiate a compromise? The meeting will present an overview of the current state of research, practice and progress in the field of paper conservation. The specific topics that will be presented in the Interim Meeting are: - Reflections on treatment decisions and processes, particularly concerning case-studies in paper conservation. - Conservation of graphic documents in the digital age: decision making, compromise and collaboration between conserving analogue cultural heritage and providing digital access to this heritage. To which extent are ethics in paper conservation affected by digitization? - Paper conservation in the era of ‘blockbuster’ exhibitions: the influence of exhibitions on decisions in conservation - Latest scientific research on characteristics, degradation and conservation of paper, parchment and papyrus: How do results of research impact choices in conservation?status: publishe