🚀 go-pugleaf

In article <1992Jul31.004008.12449@unlinfo.unl.edu> cbettis@unlinfo.unl.edu (clifford bettis) writes:
>In <1992Jul30.162250.20808@unlinfo.unl.edu> cbettis@unlinfo.unl.edu (clifford bettis) writes:
>>In <12583@inews.intel.com> bhoughto@sedona.intel.com (Blair P. Houghton) writes:
>>>In article <1992Jul29.141543.12833@unlinfo.unl.edu> cbettis@unlinfo.unl.edu (clifford bettis) writes:
>>>>The optical phase information is lost in the recording
>>>>process (i.e. the TV camera only records intensity) and therefore the 
>>>>information necessary to reconstruct a complete image is missing. 

>>>[Phase information doesn't matter.]

>>[It] does matter.  To deblur an out of focus image you need to do a fourier
>>transform (in general a fresnel transform); you can think of a lens as
>>a analog device for doing spatial fourier transforms of images.  If 

I see what you're saying.  A point of light (the real kind,
not that imaginary top-pap propounded by GHW Bush) creates
a wavefront that impinges a surface in different places at
different times.  The surface of the cornea is one such
surface, and after the lens is done with it the light is
transformed (merely bent, in this case) properly for
impinging on the retina in such a way as to produce the
virtual image without further processing (other than
rectification, since the image is inverted).

However, the retina is blessed with a feature called
"persistence of vision."  This means that it is only
intensity and duration which determine the image on the
retina.  With one eye closed, you can't tell whether the
image is from a picture or a real scene (with depth) or
even a moving scene (various spinning-disk illusions come
to mind).

But the retina first requires the image to be in-focus; it
isn't capable of creating much focus (it is capable of
some; I, for one, see poorly with one eye, even with my
glasses on, but when I use both eyes my acuity improves by
an order of magnitude).  The entire eye system does require
the phase information.

Still, your thesis is incorrect.  A TV camera, having a
lens within it, does use the phase information in doing
this spatial transform, then presents the image to its
artificial retina (a CCD or, for you old farts, a
vidicon).  Other systems, night-vision goggles in
particular, do about the same thing, then provide
additional real-time processing (in this case
photomultiplication).

The right transparent hologram could do not much less.

				--Blair
				  "Making a spectacle of myself."