Newsgroups: sci.image.processing
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!europa.eng.gtefsd.com!howland.reston.ans.net!wupost!waikato!canterbury.ac.nz!otago.ac.nz!bifrost.otago.ac.nz!nmein
From: nmein@bifrost.otago.ac.nz (Nick Mein)
Subject: Re: Watershed algorithm shortcut?
Message-ID: <D0F63v.6K0@news.otago.ac.nz>
Sender: usenet@news.otago.ac.nz (News stuff)
Nntp-Posting-Host: bifrost.otago.ac.nz
Organization: University of Otago
X-Newsreader: TIN [version 1.1 PL8]
References: <3bvdpg$sp8@news.CCIT.Arizona.EDU>
Date: Wed, 7 Dec 1994 02:40:43 GMT
Lines: 28

Te-Shen (Dickson) Liang (liang@mipl.ece.arizona.edu) wrote:

>  You said "get good results". I wonder if the results you got consists only
>  the catchment basins. That is, there is no watershed pixel after the final
>  flooding ? 

Thats right.

>  If that is true, isn't it one of the reason for the displaying
>  of the watershed pixels is to demonstrate the result of segmentation ?

Well, I suppose that my question is - exactly what _is_ the significance
of the WSHED pixels? Are they only "cosmetic", or are they necessary for
the correct operation of the algorithm?

>  If there are no wshed pixels in the final image, how could you 
>  "visualize" the watershed segmentation ? You probably will say
>  you can visualize the result by coloring the different catchment basins. But
>  what if the number of catchment is over 255 ? You won't tell the gray level
>  difference between 255 and more. Any comment ?

The purpose of the segmentation itself (in my case) is to extract
regions for further processing. To visualise the results of the
segmentation (both before & after the further processing) I draw
outlines arround the regions - effectively drawing in the watershed
pixels.

Nick.
