P3D Re: Stereo Nomenclature

[Bruce Springsteen <bsspringsteen@xxxxxxxxx>]

[I received no Digest 3673, so if I seem to have missed anyone's posting
in this thread, that may be the reason.]

Abram Klooswyk:
> However, the glossary *definition* of the term orthostereoscopy does
> not include any distances or angles.
> Theoreticians have formulated conditions which, when fulfilled,
> would give an orthostereoscopic image. Some even have said that
> those conditions are obligatory. Formulating different conditions is
> possible without changing the meaning of "orthostereoscopy".
> 
> Still the definition does not include conditions, and from a
> stereo perception point of view it is unlikely that precise
> conditions are important.

>From the standpoint of describing perception - but as Mark Dottle said,
let's eventually get back to photography (or drawing or computer graphics)
and when we do, the meaning of ortho must become more concrete, with
angles and conditions specified in terms that are sufficiently general to
serve all the various practitioners of stereo, or so I have suggested. 
That's where good old geometry can fill the bill, and it's the focus of my
"definitions".  Now who's the practical man? ;-)  

> Dalgoutte said:
> Orthostereoscopic image -  one having 'right-looking solidity',
> in which the space-image resembles the original closely, but is
> not truly 'tautomorphic' (as in gigantism and lilliputism).
> 
> Tautomorphic image - one which has the 'same form and scale and
> position' as the original object, where stereomagnification = 1.

I really like that term "stereomagnification".  Never saw it before.  We
should try to spread its use in this influential forum, and thus to the 3D
commmunity, IMHO.

> In Donald Wratten's new draft the latter is expanded to:
> Tautomorphic image   - A stereoscopic image which
> presents the original scene to the viewer exactly as it would
> have been perceived  in life; ie, with the same apparent
> scale, positions of scenic elements, and a stereo
> magnification of x 1 for all subject matter in the view.
> 
> The term "tautomorphic" seems not to be used very often, its
> definition describes what mostly is meant with "orthostereoscopic"
> on this list. But by strict definition the terms are different.

So, if ISU adopts this standard, my more limited view of orthostereoscopy
will be, in a sense, the orthodox one? (To the extent that ISU is an
authoritative body.) I favor that!  Hold the mob, Larry.

> Note 1: The origin of the terms goes much longer back than 1967.
> Note 2: "Ortho" is used sometimes as abbreviation for
>               orthoscopic, which is the opposite of pseudoscopic.

Are Donald Wratten's proposed standards available to the general
membership?  And is there a statement of purpose and scope of this
project.  Also, can someone tell me more about the standardization work
that Andrew Woods has mentioned here?  I suppose I need to catch up on
what the authoritative bodies are up to.

Bruce (If you can measure it, it's there.) Springsteen
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