Glint impression and diffuse coarseness

Looking into special surface effects: diffuse coarseness and glint impression

(Published in Coloration Technology, Volume 132, Issue 2, Pages 153–161, April 2016 , DOI: 10.1111/cote.12203)

glint sample

How do human understand and distinguish sparking (glint) and graininess (coarseness).

We conducted a psychophysical experiment to model these two effects.

glint geometry

And if you compare the visual result with instrumental measurement, you will find one dimension is not enough to represent human response.

glint dimensions

We used multidimensional scaling to find the feasible dimensionality (2 dimensions are better and not redundant).

glint mds

and then, if we represent the data into 2 dimensions, what is actually the principle axis, what is the adjunct axis. And what are the meanings of them?

Interested in this types of research topic? Please refer to my paper here.