“New Reflection Transformation Imaging Methods for Rock Art and Multiple-Viewpoint Display”

VAST 2006 Best Paper Award

Highlight RTI method using black sphere with specular highlights

About This Publication

Authors	Mark Mudge, Tom Malzbender (HP Labs), Carla Schroer, Marlin Lum
Presented at	VAST 2006, The 7th International Symposium on Virtual Reality, Archaeology and Cultural Heritage
Date and Location	November 2006, Nicosia, Cyprus
VAST 2006 Editors	M. Ioannides, D. Arnold, F. Niccolucci, K. Mania
PDF File	Download (604 KB PDF)
PDF Slide Presentation	Download (576 KB PDF)

Abstract

In this 2006 paper, we offer two new methods of documenting and communicating cultural heritage information using Reflection Transformation Imaging (RTI). One imaging method is able to acquire Polynomial Texture Maps (PTMs) of 3D rock art with a wide range of sizes, shapes, and environmental contexts. Unlike existing PTM capture methods requiring known light-source positions, we rely on the user to position a handheld light source, and recover the lighting direction from the specular highlights produced on a black sphere included in the field of view captured by the camera. The acquisition method is simple, fast, very low cost, and easy to learn. A complementary method of integrating digital RTI representations of subjects from multiple viewpoints is also presented. It permits RTI examination “in the round” in a unified, interactive, image-based representation. Collaborative tests between Cultural Heritage Imaging, Hewlett- Packard Labs, and the UNESCO Prehistoric Rock-Art Sites in the Côa Valley, a World Heritage Site in Portugal, suggest this approach will be very beneficial when applied to paleolithic petroglyphs of various sizes, both in the field and in the laboratory. These benefits over current standards of best practice can be generalized to a broad range of cultural heritage material.