[Insight-users] component trees

[Gaëtan Lehmann]

Le 22 déc. 08 à 18:35, David Pastor a écrit :

> Hello,
>
> After going in depth in both alternatives I've had to back off and  
> use the component tree instead of the one implemented in the issue  
> 203.
>
> The reason is that it is not trivial to obtain a LabelObjet-based  
> image (LabelMap or collection) from the output of the Attribute  
> Opening Filter. That filter outputs an itk::image with flatzones of  
> different levels which is hard to label.
>
> However the component tree allows me to create a Binary or Label  
> itk::Image which I can easily convert into a LabelMap and work with  
> the LabelObjects.

The component tree contribution gives more flexibility, but gives not  
as good performance - just a matter a choice.
You can use itk::RegionalMaximaImageFilter to find the flat zones  
produced by the opening.

>
> I do the following
>
>       myimagetoopen  -->  ImageToMaximumTreeFilter  --->  
> componentTree (sets full connectivity)
>       componentTree   --> SizeComponentTreeFilter  --->  
> componentTree ??? I'm not sure about what this does...

It computes the size (area or volume, depending on the dimension of  
your image) of the nodes.

>       componentTree   --> AttributeFilteringComponentTreeFilter -->  
> filteredTree (lambda = area in pixels)
>
> **Which is the attribute type and filtering type I need to use for  
> an area opening???

With that attribute (Size), the type should be unsigned long or long.
The type of filtering is not important IIRC, because all the types  
should gives the same result with that attribute. Just use the default  
one.

>
>       filteredTree         -->  
> ComponentTreeLeavesToBinaryImageFilter  --> binaryImage
>
> This image contains only the connected components with an area  
> bigget than Lambda and then I obtain a collection of LabelObjects.
>
> Does it sound correct?
>

Yes, it does!

Gaëtan


-- 
Gaëtan Lehmann
Biologie du Développement et de la Reproduction
INRA de Jouy-en-Josas (France)
tel: +33 1 34 65 29 66    fax: 01 34 65 29 09
http://voxel.jouy.inra.fr  http://www.mandriva.org
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