Hi ng,
I´m trying to understand a case of brightness-/contrast adaptation of
our visual system. In a well written review about nonlinear mappings of
intensities by Charles Poynton
(http://www.poynton.com/papers/SMPTE_93_Gamma.html) I found the
following statement:
"As I explained in the Perception section, human vision adapts over an
extremely wide range of viewing conditions. One of the ways that human
vision accommodates this huge range is to increase its sensitivity to
small brightness variations when the area of interest is surrounded by
bright elements. Intuitively, light from a bright surround can be
thought of as spilling or scattering into all areas of our vision,
including the area of interest, reducing its apparent contrast. Loosely
speaking, the effect is similar to "flare", and the visual system
compensates for it by "stretching" its contrast range to increase
the visibility of dark elements in the presence of a bright surround.
Conversely, when the region of interest is surrounded by relative
darkness, the contrast range of the vision system decreases: our
ability to discern dark elements in the scene decreases."
I appologize for the lengthy quote, but I think it is unavoidable.
Now I understand a little bit about lateral inhibition and how it works
in case of simultaneous brightness contrast, but can anybody tell me if
lateral inhibition is also involved in the above stated context that
might be called surround effect?
Best regards!
Tony Adams
