Back to articles
General Papers
Volume: 48 | Article ID: art00013
Image
A Micro-Goniophotometer and the Measurement of Print Gloss
  DOI :  10.2352/J.ImagingSci.Technol.2004.48.5.art00013  Published OnlineSeptember 2004
Abstract

The focus of this report is on the development of an instrument for measuring gloss light. The word “gloss” is intuitively easy to understand, but making an optical measurement that correlates well with the perception of gloss remains an unsolved challenge. The hypothesis behind this project is that both spatial resolution (micro-) and angular resolution (gonio-) are required of an instrument in order to correlate meaningfully with visual perceptions of gloss and also with underlying causes of gloss. Thus, a micro-goniophotometric instrument was developed. The instrument employed plain polarized light to separate bulk, diffuse light from specular light. Specular light was defined instrumentally as the difference between the light captured with a polarizing filter orthogonal to and parallel to the direction of polarization of the incident light. In addition, it was assumed that the instrument must be able to account quantitatively for all of the gloss light from the surface distributed in all directions around the specular (equal/opposite) angle. The instrument developed in this project measures specular and diffuse light as a surface radiance distributed over angle α from the specular direction in the plane defined by the sample, detector, and illuminator. The orthogonal angle, β, is not scanned. Rather, all of the light distributed in the β direction is integrated at each angle α. The area under the bidirectional reflectance factor friction, BDRF, generated in this way accounts for all of the specular light distributed over both angles α, and β. Using this instrument, it was shown that the effects of surface roughness could be differentiated from the effects of variations in refractive index. In addition, the color of the light and the ink were measured and found to vary the amount of specular reflectance by as much as a factor of two. A mechanism is proposed to account for this.

Subject Areas :
Views 1
Downloads 0
 articleview.views 1
 articleview.downloads 0
  Cite this article 

J. S. Arney, Hoon Heo, P. G. Anderson, "A Micro-Goniophotometer and the Measurement of Print Glossin Journal of Imaging Science and Technology,  2004,  pp 458 - 463,  https://doi.org/10.2352/J.ImagingSci.Technol.2004.48.5.art00013

 Copy citation
  Copyright statement 
Copyright © Society for Imaging Science and Technology 2004
  Login or subscribe to view the content