Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!uwm.edu!cs.utexas.edu!uunet!mcsun!cernvax!ethz!keller
From: keller@ethz.UUCP (Christoph Keller)
Newsgroups: comp.graphics
Subject: Re: 3D shape fitting
Summary: This is a common problem in solar physics
Keywords: 3D SHAPE ANALYSIS
Message-ID: <2311@ethz.UUCP>
Date: 23 Oct 89 11:46:33 GMT
References: <134@adam.ua.oz>
Reply-To: keller@bernina.ethz.ch.UUCP (Christoph Keller)
Followup-To: comp.graphics
Distribution: comp.graphics
Organization: ETH Zuerich, Switzerland
Lines: 43


George writes:

> could someone give me a pointer to an algorithm that may be able to 'fit'
> two meshes together. more specifically i have two regular meshes which 
> represent iso-surfaces. i want to see how close 'in a lock and key' sense
> they fit together. i cant use least squares because there are no identifiable
> or corresponding landmarks on the two meshes, which are meshes generated
> through arbitrary data.
> you can imagine a mesh with a hill and another mesh with a trough, how can
> you determine how close they can be made to correspond?
> --GeO                     George Travan
> 			  e-mail:  gtravan@adam.ua.oz
> 				   george@frodo.ua.oz

This is a common problem in solar physics. The Earth's atmosphere is
distorting sequentially observed images through the randomly changing
refractive index of the atmosphere. This distortion needs to be removed
when comparing images of the same region on the sun obtained at
different times. Here are some references:

von der Luehe, O.: A study of a correlation tracking method to improve 
  imaging quality of ground based solar telescopes, Astron.Astrophys.
  119, p.85

November, L.J.: Measurement of geometric distortion in a turbulent
  atmosphere, Applied Optics, Vol.25,No.3, p.392

Keller, C.U.: Restoration of distorted images as a variational problem:
  A dynamic programming approach, NOAO Preprint No. 229
  (I can mail this article by e-mail, but without figures)

Hope this helps,

Christoph

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Christoph Keller                        keller@czheth5a.bitnet
Institute of Astronomy                  ckeller@solar.stanford.edu
ETH-Zentrum                             keller@ifa.ethz.ch
CH-8092 Zuerich                         keller@bernina.ethz.ch.uucp
Switzerland
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