Global Illumination Compensation for Spatially Augmented RealityYu Sheng, Theodore C. Yapo, and Barbara Cutler
To appear in Computer Graphics Forum, Eurographics 2010
paper (pdf, 34M)     video (mpg format, 17M)
Abstract: When projectors are used to display images on
complex, non-planar surface geometry, indirect illumination between
the surfaces will disrupt the final appearance of this imagery,
generally increasing brightness, decreasing contrast, and washing out
colors. In this paper we predict through global illumination
simulation this unintentional indirect component and solve for the
optimal compensated projection imagery that will minimize the
difference between the desired imagery and the actual total
illumination in the resulting physical scene. Our method makes use of
quadratic programming to minimize this error within the constraints of
the physical system, namely, that negative light is physically
impossible. We demonstrate our compensation optimization in both
computer simulation and physical validation within a table-top
spatially augmented reality system. We present an application of these
results for visualization of interior architectural illumination. To
facilitate interactive modifications to the scene geometry and desired
appearance, our system is accelerated with a CUDA implementation of
the QP optimization method.
Comparison of different algorithms. Our result is definitely better than the clamped inverse and least squares method, and comparable with non-linear optimization in L*a*b* color space
This material is based upon work supported by the National Science Foundation under Grant No. CMMI 0841319 and Grant No. IIS 0845401. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
This work was also supported by a grant from IBM.