[Insight-users] About Level sets

[rashedk]

Thanks for your reply Luis, and I am glad to know that this is possible using
ITK. 

But I dont understand what I need to put into this *speed image*. Is this a
binary image or grey-scale? Can you give me an example of what a speed image
would contain if the propagating front speed was governed by the image's
intensity gradient magnitude?  

Thanks for your reply, I really appreciate. 

Regards,
Rashed karim 



Luis Ibanez wrote:
> 
> 
> Hi Rashed,
> 
>                      Yes, it is possible.
> 
> 
> Note that, for example, in FastMarching, *you* build the
> speed image. Therefore, you can simply precompute the images:
> 
>     a) Gradient magnitude
>     b) Vesselness
> 
> and combine them in any way you want to generate the speed image.
> It seems, for example, that a multiplication of the two images will
> produce the "AND" effect that you are looking for.
> 
> 
> Then, finally, pass the computed speed image to the FastMarching
> filter, as you have already seen it described in the ITK Software
> Guide.
> 
> 
> If you want to make a more sophisticated mixture of terms,
> then you can easily write your own LevelSet filter, by still
> reusing the ITK framework. In this case, you have to write
> two classes:  X_LevelSetImageFunction and X_LevelSetImageFilter.
> In this scenario, you will find useful to look at the code
> implementing other LevelSet filters.
> 
> 
> Also, since you are interested in Vessel segmentation, you may
> find useful the following paper posted in the Insight Journal:
> 
> 
> "Generalizing vesselness with respect to dimensionality and shape"
> by Antiga, Luca
> http://www.insight-journal.org/InsightJournalManager/view_reviews.php?back=search.php%3Ftexte%3Dvessel&journalid=9&pubid=175
> 
> 	
> "Vessel Enhancing Diffusion Filter"
> Enquobahrie, Andinet; Ibanez, Luis; Bullitt, Elizabeth; Aylward, Stephen
> http://www.insight-journal.org/InsightJournalManager/view_reviews.php?back=search.php%3Ftexte%3Dvessel&journalid=8&pubid=163
> 
> 
> 
> If you find these papers useful, you are strongly encouraged to
> support OPEN ACCESS by posting reviews to the papers. Please note
> that the reviews of the Insight Journal are not intended to be the
> empty reviews of decadent traditional journals where the reviewers
> simply speculate on what "they think" about the paper. On the contrary
> the Insight Journal expects comments from fellow developers of image
> analysis software who *actually* compiled and run the source code that
> is accompanying the paper, and report on their experience on the use
> of the code.
> 
> 
> 
>     Peer-review without reproducibility is mindless babbling.
> 
>     We already have had enough of that in our field...
>     It is time to raise from the muddy waters of narcissism
>     and move our field up to the standards of scientific work.
> 
> 
> 
> By the same token, If you find a way of integrating the two images
> as input to your level set filter, you are also *strongly encouraged*
> to submit your work as a paper to the Insight Journal. Here again,
> papers to the Insight Journal are not about the childish quest for
> "originality" claims that disgustingly plague the decadent journals
> of our field. Instead, we expect your paper to demonstrate that the
> practical solution that you found to your real image processing
> problem, actually works. The demonstration is provided not by textual
> arguments in your paper, but by the source code, parameters, images,
> and instructions that you provide, describing how to *REPRODUCE* your
> tests.
> 
> 
>   Please let us know if you have any further questions,
> 
> 
>      Thanks
> 
> 
>         Luis
> 
> 
> 
> ------------------
> rashed karim wrote:
>> Hi Everyone,
>> 
>> Is it possible to use the ITK level set implementations (such as Fast 
>> marching, Geodesic, Laplacian, etc.) to drive a propogating front whose 
>> speeds are governed by let's say two factors: 1. Gradient magnitude 2. 
>> Frangi's vesselness. I want the propagating front to stop speeding at 
>> points which give high responses to the vesselness filter AND have high 
>> image gradient magnitudes.
>> 
>> Does ITK level set implementations allow users to define their own 
>> criterion which limits the speed of the active contour? I have had a 
>> good look at the ITK software guide, and it seemed like this isn't 
>> possible.
>> 
>> Thanks in advance,
>> 
>> Regards,
>> Rashed Karim
>> 
>> 
>> ------------------------------------------------------------------------
>> 
>> _______________________________________________
>> Insight-users mailing list
>> Insight-users at itk.org
>> http://www.itk.org/mailman/listinfo/insight-users
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
> 
> 

-- 
View this message in context: http://www.nabble.com/About-Level-sets-tf4293212.html#a12225162
Sent from the ITK - Users mailing list archive at Nabble.com.