Related CHI Projects

Gold coin from Grand St. Bernard

Learn about CHI's work in Switzerland in 2005, including the imaging of gold coins and other artifacts at the collection Archeologique du Musée de l'Hospice du Grand St. Bernard: see our Switzerland 2005 project page for more information.

CHI's Carla Schroer with Swiss gold coin collection

See also our Technologies Overview page, and learn more about Reflectance Transformation Imaging (RTI).

“Reflection Transformation Imaging and Virtual Representations of Coins from the Hospice of the Grand St. Bernard”

Julian Star with Specular Enhancement

Julian Star with Specular Enhancement

About This Publication

Authors Mark Mudge, Jean-Pierre Voutaz, Carla Schroer, Marlin Lum
Presented at VAST 2005, The 6th International Symposium on Virtual Reality, Archaeology and Cultural Heritage
Date and Location November 9, 2005, Cyprus, Greece
VAST 2005 Editors M. Mudge, N.Ryan, R. Scopigno
PDF File Download (604 KB PDF)


Reflection Transformation Imaging (RTI) offers a powerful new method of documenting and communicating numismatic cultural heritage information. The challenges of documenting numismatic material will be examined along with the limitations of traditional documentary techniques. Previous uses of structured light scanning and Polynomial Texture Maps (PTMs) in numismatic documentation are reviewed and evaluated. A novel, low-cost method for capturing PTMs at remote locations and subsequent data processing operations is described. Reflection Transformation Imaging is shown to capture more complete documentation than traditional photographic methods and communicate this information with ease through digital media. The advantages of interactive relighting of numismatic PTM images in conjunction with enhancement operations are explored, along with the potential of informed choice of the most information-rich illumination directions. Advantages of joint capture of structured light and PTMs are examined, including the inherent registration of range and normal data, using range and normal information together to improve 3D position accuracy, and the enhanced evidentiary reliability that results.