Extraction of Characteristics of Solid Pigments from Paint Samples

Abstract

Modern automotive paints have a complex structure and consist of a variety of pigments including the solid ones. There are many tasks related to the correct color reproduction of the automotive paints. But the most practical one is the color matching: obtaining of paint composition needed to get the specified color. This task can be solved with help of lighting simulation inside paint structure. But we have to know optical properties of the paint pigments to do so. In the paper we propose and verify robustness of several different methods to extract pigment properties from the measured BRDFs. All methods are based on fitting of calculated visual appearance to the measured one. The methods differ in sets of the real paint samples which have to be prepared to extract pigment data. We describe operation of the methods and verify their robustness. It happened that among proposed methods one is much more accurate, while others produced significant errors.