Measurement and Modeling of Bidirectional Characteristics of Fluorescent Objects

A method is proposed for measurement and modeling of bidirectional characteristics of fluorescent objects. First, a gonio-spectro measurement system is constructed for measuring the spectral luminescent radiance factor of a variety of fluorescent object surfaces. Second, the angular dependency of the luminescence radiance factor is analyzed in different light incidence and viewing directions. The observed radiance factors can then be described by the Lambertian model with good accuracy. We also analyze the bidirectional reflection radiance factor of a white mat surface. The whole characteristics of bispectral bidirectional radiance factors of a fluorescent object can be summarized as a compact mathematical model. Finally, image rendering of a fluorescent object is performed using the Donaldson matrix estimated in a separate measurement system. The feasibility of the proposed method was examined experimentally.