T3D Re: Visual acuity resolved

["Jim Crowell" <crowell@xxxxxxxxxxxxxxx>]

>
>What I'm working up to here is that 1' is really more 
>correct than 2' for an absolute visual acuity.  The next
>thing that occurs to me is that the eye isn't perfect so it 
>has a spread function of some sort for light so to get the
>best acuity, you might want to slim down the white lines
>relative to the black lines: don't make them equal width
>or thickness, however you want to call it.  That way when
>the white light bleeds out of its bounds in the eye, it 
>will still leave lots of black between the white lines.
>You need that black for the contrast.  I think contrast is
>the key.  We need very little of it to make out an image
>but we do need to have some.
>

Right.  By doing this you can increase the contrast of the fundamental
Fourier component of the pattern (if you break the pattern down into a
sum of sinusoids, the fundamental is the lowest frequency--i.e.
coarsest--component) above 100%.  (Where contrast of a sinusoid is
defined as the amplitude divided by the mean).

-Jim C.

----------------------
Jim Crowell
Caltech Division of Biology
Mail Code 216-76
1200 E. California Blvd.
Pasadena, CA 91125
Tel: (626) 395-8337
Fax: (626) 795-2397
jim@xxxxxxxxxxxxxxx
http://vis.caltech.edu/~jim/Home.html


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End of TECH-3D Digest 334
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