Newsgroups: sci.image.processing
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From: koller@ecrc.de (Dieter Koller)
Subject: Re: Detect the depth of image
Message-ID: <D17H5r.7Ep@ecrc.de>
Sender: news@ecrc.de
Reply-To: koller@ecrc.de
Organization: "European Computer-Industry Research Centre GmbH, Munich, Germany"
References:  <3cr5oh$872@news.csie.nctu.edu.tw>
Date: Thu, 22 Dec 1994 09:32:14 GMT
Lines: 32

In article <3cr5oh$872@news.csie.nctu.edu.tw>, s821735@moon.yzit.edu.tw (ahan) writes:
> Hi, everybody !
> 
>    Is there existing a simple algorithm to detect the depth(or range) of 
> image's pixel ? Thanks!
>                  E-mail: s821735@moon.yzit.edu.tw

No! It's an ill-posed problem.
There are various approaches to tackle it. Most of them with limited applicability.
Approaches to recover the depth (or the 3D shape) are devided into the following
categories:

* shape-from-stereo (use two or more cameras to get multiple views)
* shape-from-motion (exploit motion to get multiple views)
* shape-from-shading (assume certain reflection behaviour)
* shape-from-texture (assume the same texture on the surface)
* shape-from-focus (exploit the fact that the focal plane has only a certain extent)

There are some nice theories but *no* simple algorithm. You may find an
acceptable solution for a certain application. Check the standard Computer
Vision (CV) literature (e.g. Horn's book), the vision journals (e.g. Int'l 
Journal of Computer Vision [IJCV], IEEE Trans. on Pattern Analysis and Machine 
Intelligence [PAMI] ...) and the Proceedings of the vision conferences 
(e.g. Int'l Conf. on Computer Vision [ICCV], Conf. on Comp. Vision and Pattern 
Recognition [CVPR] ... ) and you may find and adapt an appropriate approach. 

 - Dieter

-- 
 Dr. Dieter KOLLER
 European Computer-Industry Research Centre   Tel: +49 (89) 92699-109
 Arabellastr 17, 81925 Muenchen, GERMANY.     Email:   koller@ecrc.de
