An MIT news
release describes the underlying neural mechanism researcher believe
is responsible for our ability to visually categorize surface textures.
We can tell at a glance whether a surface is a rough or glossy. The
researchers believe our brain has collections of neurons that respond to
positive or negative skewing of a luminance histogram. The asymmetry of
the histogram correlates to the surface quality. Glossy, darker surfaces
tend to be skewed positively, while rougher surfaces are skewed
negatively. There are immediately applications to machine vision, with
autonomous vehicles high on the list. Being able to easily determine if
the road is icy or dry, paved or dirt would be very useful. NTT, who
collaborated on this research, offers a more detailed summary of
the research which includes example images and histograms.