"Accurate Image Based Re-Lighting through Optimization"
Pieter Peers, and Philip Dutré

Department of Computer Science, K.U.Leuven, CW336, April 2002
In this report we present a new re-lighting technique that, for a single viewpoint, accurately captures the reflectance field of real and virtual objects, without restrictions on their geometrical complexity or material properties. As a result the objects can be re-lit under arbitrary lighting conditions. To capture the reflectance field, we take photographs of an object lit by several lighting patterns on a surrounding discretized hemicube. The illumination of each pixel due to emitted radiance from each discrete patch on the hemicube is approximated by a reflection coefficient and a rectangular support which are found through an optimization procedure. The discretization of the hemicube ensures sufficient angular sampling to capture diffuse material properties. The use of a per patch support accommodates the small solid angle of a incoming light important for specular materials. To re-light the object, the target illumination, a high-dynamic range environment map, is averaged over the support and multiplied by the reflection coefficient, per pixel and per discrete patch on the hemicube. The results obtained show accurate re-lighting of diffuse as well as specular objects.

Supplementary Material
Related Publications
  • Pieter Peers, and Philip Dutré, "Accurate Image Based Re-Lighting through Optimization", ACM SIGGRAPH 2002 Conference Abstracts and Applications, pages 145-145, San Antonio, USA, August 2002,
  • Pieter Peers, and Philip Dutré, "Accurate Image Based Re-Lighting through Optimization", Poster presentation at 13th Eurographics Workshop on Rendering, Pisa, Italy, June 2002,
author = {Peers, Pieter and Dutr\'{e}, Philip},
title = {Accurate Image Based Re-Lighting through Optimization},
month = {April},
year = {2002},
institution = {Department of Computer Science, K.U.Leuven},
number = {CW336},