title: Separation of surface and bulk reflectance by absorption of bulk scattered light.
abstract: A method is proposed for separating light reflected from turbid media with a rough surface into a bulk and a surface component. Dye is added to the sample, thereby increasing absorption and canceling bulk scattering. The remaining reflected light is surface reflectance, which can be subtracted from the total reflectance of an undyed sample to obtain the bulk component. The method is applied to paper where the addition of dye is accomplished by inkjet printing. The results show that the bulk scattered light is efficiently canceled, and that both the spectrally neutral surface reflectance and the surface topography of the undyed paper is maintained. The proposed method is particularly suitable for characterization of dielectric, highly randomized materials with significant bulk reflectance and rough surfaces, which are difficult to analyze with existing methods. A reliable separation method opens up for new ways of analyzing, e.g., biological tissues and optical coatings, and is also a valuable tool in the development of more comprehensive reflectance models.
authors.affiliation: Department of Natural Sciences, Digital Printing Center, Mid Sweden University, Örnsköldsvik SE-891 18, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Johansson
authors.forename: Magnus
authors.initials: M
authors.lastname: Neuman
authors.forename: Mattias
authors.initials: M
authors.lastname: Andersson
authors.forename: Per
authors.initials: P
authors.lastname: Edström
mesh_terms: D000042:Absorption; D004396:Coloring Agents / Q000737:chemistry; D003952:Diagnostic Imaging / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008027:Light; D008422:Materials Testing; D055095:Optics and Photonics; D010209:Paper; D012542:Scattering, Radiation; D013499:Surface Properties
chemical_list: D004396:Coloring Agents