FW: [Tig] D-Cinema Suite contd.
Sun Mar 9 05:35:52 GMT 2003
From: Richard Dean
> We found that the iris in the eye, responding to brighter images in a
> general proximity to shadows, is a player in how shadows are perceived.
I don't think it is right at all.
And, since the TIG seems to require that factual information be accompanied
by that extra-sensitive touch, I'll clarify that I say the above with the
utmost respect for you, the organization you work for and all others who
have participated in this thread.
Now, with that out of the way. This is how it works:
The iris is in charge of maintaining a certain level of illumination on the
retina. It really has very little to do with color or shadow perception
beyond getting the stimulus to be "in range". Maybe some fringe effects
here or there, but nothing to write home about.
The visual illusion this thread has been discussing is caused by a real
change of sensitivity on the retina itself. This phenomenon, known as
"lateral inhibition", produces zones in the retina that modify their
behavior based on the level of excitation in adjacent zones. A typical
example found in books might be a white card with a gray square in the
middle. The white surround stimulates retinal receptors where, of course,
the white image is projected. These photoreceptors, in turn, through
horizontal cells in the retina, produce an inhibiting "signal" that affects
the photoreceptors in the central zone, where the stimulation is different
(gray). In the absence of other data, the brain can only know about the
modified information emanating out of the eye.
A search for "lateral inhibition" should provide a good cross-section of
reference material on this subject.
Due to work outside of this industry I've been researching various aspects
of human vision for about four years. The culmination of this work will
come in a few months with the introduction of a set of goggles that uses
this knowledge to provide bio-feedback to an individual performing a certain
task. I think I can say that, as far as I know, the physical, biochemical,
neural and psychological factors in human vision are very well understood.
eCinema Systems, Inc.
martin at ecinemasys.com
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