Proceedings Article | 1 April 2020
KEYWORDS: Visualization, Reflectivity, Image processing, RGB color model, Data modeling, Tablets, Light emitting diodes, Data storage, Information visualization, Data processing, Computer vision technology, 3D scanning, Cultural heritage
Multi-light, single-camera imaging techniques like Reflectance Transformation Imaging (RTI, including PTM, HSH, and PCA-RBF) and the Portable Light Dome (PLD) have been used by cultural heritage scholars and collection curators extensively because of the extra interactive visual information that can be revealed on artefacts when compared to standard digital photography. Besides a virtual relighting of the scanned object, these techniques offer filters to accentuate different aspects of the studied surface. The main focus of RTI, developed at HP, CHI and among others elaborated by ISTI CNR, is aimed at photo-realistic virtual relighting. PLD, developed at KU Leuven, on the other hand, is aimed at extracting surface properties such as surface color (albedo), surface gradient (normals), 3D surface features (height profiles) and reflectance distribution (reflectance maps). PLD and RTI both produce interactive pixel based file formats, which are dissimilar, resulting in incompatible datasets. The pixel+ project (Art and History Museum, KU Leuven, and KBR, Belspo BRAIN-be funded) aims to merge both technologies into one web-based consultation platform, allowing existing PLD and RTI datasets to be viewed in one web environment with their respective viewing filters as well as to illuminate the virtual model. Moreover, as both methods are alike in terms of required input and processed output, pixel+ focuses on other types of integration, resulting in new viewing modes for processed data as well as a novel reprocessing pipeline for existing source images. In addition, for sustainable and flexible web consultation a new open format, based on glTF, is suggested and a first elaboration is presented.
