Re: Stars in Stereo

[crowell@xxxxxxxxxxxxxxxxx (Jim Crowell)]

At 11:33 PM 2/27/96, John Roberts wrote:
>
>Vernier acuity is important for design of display devices - placement of
>display elements has to be extremely precise to avoid visible discontinuities.
>

Definitely!  For some of the experiments we're doing (on
stereo), one of my lab-mates spent a _long_ time developing
algorithms for creating accurate anti-aliased displays (so we
could get depth displacements smaller than one pixel) and
undoing the spatial distortions in CRTs.

>I think it would be fair to say that some of these hyperacuities are a function
>of the processing capabilities of the brain - for instance in the case of
>vernier acuity, the brain has considerable hardware dedicated to detecting
>and determining the positions of edges and lines.

Agreed.  Actually, what's interesting is that vernier acuity
tells us less about how the brain works than was once thought;
it turns out that once you allow for the fact that cells in the
visual system take inputs from regions of the retina, many of
the properties of vernier acuity follow from the statistics of
retinal images...

>
>I believe someone calculated a few years ago that the maximum human stereo
>acuity would require a detection of difference in spacings which is not
>too much different from the theoretical resolution of an optical device
>with an aperture equal to the human interocular.
>

It's pretty amazing when you consider how much the eyes jiggle, I think!

-Jim C.


------------------------------------------------
Jim Crowell
U.C. Berkeley School of Optometry
360 Minor Hall, Berkeley, CA 94720
(510) 642-7679
jim@xxxxxxxxxxxxxxxxx



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