[Insight-users] Problem related to the newly submited:Implementationof a 3D thinning algorithm

[Xavier Mellado Esteban]

   Dear Flo:

   Perhaps you would try our medial curve extraction implementation 
submitted to ITK some time ago. Look at the references to see if it 
should match your needs.

   URL: http://hdl.handle.net/1926/560

                 Best regards:
                                       Xavi

   PS: We recently discovered that it is not completely working, in few 
cases it fails to extract medial curve (output is not a medial curve). 
As soon as we find the error we will update the code. If you have 
experience and time, you may want to look at the code, I think it is 
quite "clean" and "clear", so it will not be difficult try to fix it.


Flo escribió:
> Dear all:
>
> I tried to use the newly submitted Implementation of a 3D thinning 
> algorithm. However, using Colon images, I have wrong results.
> A bad behavior is illustrated here: 
> http://florent.chandelier.free.fr/ITK/Thinning_3D_Colon_bad.bmp
> A good behavior is illustrated here: 
> http://florent.chandelier.free.fr/ITK/Thinning_3D_Colon_good.bmp
> These are obtained on the same object but at different locations.
>
> As you can see, some portion of the skeleton are OK but some others 
> are really messy (Zoomed Images). Indeed, I have no holes in my object 
> but I end up with loops in the skeleton which thus modifies the Euler 
> number.
>
> On a different note, I did myself work on Skeletonization during my 
> PhD and *IF* I remember well, lee's paper (the referenced one) is not 
> an exact method as pointed out by other papers (cf Pudney, 1997 I 
> think. This is due to the cycle process while looking for the 
> neighborhood. There is no unique cycle in 3D to go through the 
> neighborhood as compared to the 2D case where there is a unique cycle 
> - clock and counter-clockwise end up being the same.)
>
> This is a great effort to implement a 3D skeletonization process for 
> ITK. Congrats to the ppl doing this. My personal view, and maybe a 
> future contribution, would be to spend more time implementing the 
> method described by Pudney, 1997 as it allows for the discrimination 
> of every skeleton type (Exact medial surface, medial trunk and medial 
> axis).
>
> I'm sorry to mail this to the news group but I do not know how the 
> reviewing process works.
>
> regards,
>
> flo.
>
>
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-- 
___________________________________

Xavier Mellado Esteban
Computational Imaging Lab
Department of Technology - D. 317
Pompeu Fabra University
Pg. Circumval·lació 8
08003 Barcelona - Spain

Phone: +34 93 542 1323
E-mail: xavier.mellado at upf.edu
Skype: xavier.mellado