Acquisition and Analysis of Bispectral Bidirectional Reflectance and Reradiation Distribution Functions
In fluorescent materials, light from a certain band of incident wavelengths is reradiated at longer wavelengths, i.e., with a reduced
per-photon energy. While fluorescent materials are common in everyday life, they have received little attention in computer graphics. Especially, no bidirectional reradiation measurements of fluorescent materials have been available so far. In this paper, we
extend the well-known concept of the bidirectional reflectance distribution function (BRDF) to account for energy transfer between
wavelengths, resulting in a Bispectral Bidirectional Reflectance
and Reradiation Distribution Function (bispectral BRRDF). Using
a bidirectional and bispectral measurement setup, we acquire reflectance and reradiation data of a variety of fluorescent materials,
including vehicle paints, paper and fabric, and compare their renderings with RGB, RGB×RGB, and spectral BRDFs. Our acquisition
is guided by a principal component analysis on complete bispectral
data taken under a sparse set of angles. We show that in order to
faithfully reproduce the full bispectral information for all other angles, only a very small number of wavelength pairs needs to be
measured at a high angular resolution.
Projects

Interactive Geometry-Aware Segmentation for the Decomposition of Kaleidoscopic Images
VMV 2012
Abstract
Mirror systems have recently emerged as an alternative low-cost multi-view imaging solution. The use of these
systems critically depends on the ability to compute the background of a multiply mirrored object. The images
taken in such systems show a fractured, patterned view, making edge-guided segmentation difficult. Further,
global illumination and light attenuation due to the mirrors make standard segmentation techniques fail.
We therefore propose a system that allows a user to do the segmentation manually. We provide convenient tools
that enable an interactive segmentation of kaleidoscopic images containing three-dimensional objects. Hereby, we
explore suitable interaction and visualization schemes to guide the user. To achieve interactivity, we employ the
GPU in all stages of the application, such as 2D/3D rendering as well as segmentation.
Video Demo Data Set Bibtex
@InProceedings{Klehm12,
author = {Oliver Klehm, Ilya Reshetouski, Elmar Eisemann, Hans-Peter Seidel, and Ivo Ihrke},
title = "{Interactive Geometry-Aware Segmentation for the Decomposition of Kaleidoscopic Images }",
booktitle = {Proceedings of VMV},
pages = "xx--yy",
year = {2012},
}
author = {Oliver Klehm, Ilya Reshetouski, Elmar Eisemann, Hans-Peter Seidel, and Ivo Ihrke},
title = "{Interactive Geometry-Aware Segmentation for the Decomposition of Kaleidoscopic Images }",
booktitle = {Proceedings of VMV},
pages = "xx--yy",
year = {2012},
}