From: tombre@loria.fr (Karl Tombre)
Newsgroups: sci.image.processing
Subject: Re: Help Wanted: Contour Tracing
Date: 26 Jan 93 08:11:45 GMT
Reply-To: tombre@loria.fr
Organization: INRIA Lorraine, Nancy, France
In-reply-to: scotj@pinet.aip.org's message of 21 Jan 93 19:26:19 GMT

In article <1993Jan21.192619.10241@pinet.aip.org> scotj@pinet.aip.org (scot_shinderman) writes:

      While reading the standard image processing books I have noticed one
   algorithm that seems to be glossed over: contour tracing.  In the
   pictures that I am scanning, a filter is run across the pixels and a
   threshold is applied to produce either white or black pixels for the
   grey-scale.  At this point there is usually a rather disconnected set of
   dots due to noise in the picture but also some strong edges from the
   filter.  What is the "pratical" method of moveing along the detected
   pixels to find lines (or curves).  If I try to step from one pixel to
   the next by looking in a neighborhood, then the path almost always gets
   caught up in the noise off to one side or another.  Is there a way to
   "nudge" the search in a particular direction based on previous motions.

Here are some references:

@STRING{pami = {IEEE Transactions on PAMI}}
@STRING{scia87 = {Proceedings of 5th Scandinavian Conference on Image Analysis, Stockholm (Sweden)}}
@STRING{prl = {Pattern Recognition Letters}}
@STRING{cgip = {Computer Graphics and Image Processing}}
@STRING{cg = {Computer Graphics}}

%		--------------------------------
@INPROCEEDINGS{giraudon87a,
	AUTHOR = {G. Giraudon},
	TITLE = {{An Efficient Edge Following Algorithm}},
	YEAR = {1987},
	BOOKTITLE = scia87,
	VOLUME = 2,
	PAGES = {547--554}
}
%		--------------------------------
@ARTICLE{meer90b,
	DATE = {Fri Jun 15 1990},
	AUTHOR = {P. Meer and C. Allen Sher and A. Rosenfeld},
	TITLE = {{The Chain Pyramid: Hierarchical Contour Processing}},
	YEAR = {1990},
	JOURNAL = pami,
	PAGES = {363--376},
	NUMBER = {4},
	VOLUME = {12}
}
%		--------------------------------
@ARTICLE{xie92a,
	DATE = {Tue Mar 10 1992},
	AUTHOR = {M. Xie and M. Thonnat},
	TITLE = {{An Algorithm for Finding Closed Curves}},
	YEAR = {1992},
	JOURNAL = prl,
	PAGES = {73--81},
	NUMBER = {1},
	VOLUME = {13}
}
%		--------------------------------
@ARTICLE{xie92b,
	DATE = {Mon Nov  2 1992},
	AUTHOR = {M. Xie},
	TITLE = {{Edge Linking by Using Causal Neighborhood Window}},
	YEAR = {1992},
	JOURNAL = prl,
	PAGES = {647--656},
	VOLUME = {13},
	MONTH = {September}
}
%		--------------------------------
@ARTICLE{chakravarty81a,
	DATE = {Wed Dec  2 1992},
	AUTHOR = {I. Chakravarty},
	TITLE = {{A Single-Pass, Chain Generating Algorithm for Region Boundaries}},
	YEAR = {1981},
	JOURNAL = cgip,
	PAGES = {182--193},
	VOLUME = {15}
}
%		--------------------------------
@ARTICLE{rosenfeld78a,
	DATE = {Fri Dec 11 1992},
	AUTHOR = {A. Rosenfeld},
	TITLE = {{Algorithms for Image/Vector Conversion}},
	YEAR = {1978},
	JOURNAL = cg,
	PAGES = {135--139},
	VOLUME = {12},
	MONTH = {august}
}
--
Karl Tombre - INRIA Lorraine / CRIN-CNRS     --- Email: Karl.Tombre@loria.fr
Post: Batiment LORIA, BP 239, 54506 Vandoeuvre CEDEX, France --or--
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Newsgroups: sci.image.processing