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From: sarrel@tut.UUCP
Newsgroups: comp.sys.mac
Subject: Re: 3-D Graphics Question
Message-ID: <2329@tut.cis.ohio-state.edu>
Date: Thu, 26-Nov-87 01:44:56 EST
Article-I.D.: tut.2329
Posted: Thu Nov 26 01:44:56 1987
Date-Received: Sun, 29-Nov-87 03:44:57 EST
References: <1259@saturn.ucsc.edu>
Organization: The Ohio State University Dept of Computer and Information Science
Lines: 45

In article <1259@saturn.ucsc.edu> johnroc@ssyx.ucsc.edu (John Rocchio) writes:
>I have digitized a photo of an African village taken from an unknown
>altitude and an unknown angle.  I am wondering if anyone can recommend
>a program that can take this image and rotate it in 3-D so that I can
>get an idea of the exact size of the fences surrounding the village, 
>from all angles.

I tried to send mail, but the mailer bounced the letter back.  Sorry.

=====

The program you're asking for is in the area of computer vision.  Such a
program would be able to recognize the different elements in the picture
(fences, buildings, etc) and construct an internal model of the scene.
Once the internal model is constructed, any old 3D graphics display
program could display it from any angle.

However, the program to do that recognition probably hasn't been written
yet.  I'm not an expert on computer vision.  My area of interest here in
grad school is computer gaphics.  However, I'm taking a computer vision
course next quarter, so I guess I'll be and expert real soon :-).  But,
seriously, from what I know, the computer vision software that's been
written works only on a very limited domain of objects.  If you were to
give your picture to such a program, it probably wouldn't give correct
results.

Even if such a program existed, it would be part of someone's research
project and probably wouldn't be written for the Mac.  Don't get me
wrong, what you suggest is a wonderful and perfectly valid idea.  The
only problem is that you're several (many?) years too early.

Recognizing objects in a photograph and contructing a 3D model is
something that the human mind does very well, but that computers are not
able to do yet.  I'm sure that the U.S. government would love to be able
to do this sort of thing witht their spy sattelites.  However, if they
can, they ain't saying how.

Sorry to throw a wet towel on your idea, but I hope I helped.  If you
find out something significantly different from what I said, please let
me know.  I'd be interested to learn about it.
-- 
Marc Sarrel			The Ohio State University
611 Harely Dr #1		Department of Computer and Information Science
Columbus, OH  43202-1835	sarrel@tut.cis.ohio-state.edu
Disclaimer:  Hey, what do I know?  I'm only a grad student.