Re: eyes & keystoning

[T3D Jim Crowell <crowell@xxxxxxxxxxxxxxx>]

At 12:32 PM -0700 5/29/97, T3D John Bercovitz wrote:
>John R writes:
>> Come to think of it, I wonder whether the human
>> visual system ever uses keystoning as a depth cue.
>
>So how do you visualize keystoning as being a depth
>cue?  (It feels funny calling it "keystoning" when
>it's an image on a spherical surface but I don't
>know what else to call it.)
>

Not exactly, but it is used in the interpretation of horizontal disparities
for perception of surface slant & curvature. In other words, although it
doesn't affect the perceived distance to a surface, the visual system acts
like it's using it to estimate distance as part of the computation of
surface slant & curvature.

Was that sufficiently confusing?  :-)

-Jim C.


----------------------
Jim Crowell
Caltech Division of Biology
216-76
Pasadena, CA
Tel: (818) 395-8337
Fax: (818) 795-2397
jim@xxxxxxxxxxxxxxx



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