"Image-based appearance acquisition of effect coatings" by Jiří Filip and Radomír Vávra

Article Title

Image-based appearance acquisition of effect coatings

Authors

Jiří Filip, The Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodárenskou věží4, 185 08,Praha 8, Czech Republic.
Radomír Vávra, The Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodárenskou věží4, 185 08,Praha 8, Czech Republic.

Keywords

effect coatings, measurement, bidirectional texture function (BTF), appearance, psychophysical experiment

Abstract

Paint manufacturers strive to introduce unique visual effects to coatings in order to visually communicate functional properties of products using value-added, customized design. However, these effects often feature complex, angularly dependent, spatially-varying behavior, thus representing a challenge in digital reproduction. In this paper we analyze several approaches to capturing spatially-varying appearances of effect coatings. We compare a baseline approach based on a bidirectional texture function (BTF) with four variants of half-difference parameterization. Through a psychophysical study, we determine minimal sampling along individual dimensions of this parameterization. We conclude that, compared to BTF, bivariate representations better preserve visual fidelity of effect coatings, better characterizing near-specular behavior and significantly the restricting number of images which must be captured.