[Insight-users] are itkConnectedComponentImageFilter and itkBinaryDilateImageFilter

[Gaëtan Lehmann]

Hi,

For BinaryDilateImageFilter, it is possible to take the spacing into  
account when choosing the kernel size - the size on the third  
dimension should be three time smaller than on the two other ones -  
for example [3,3,1]. There is nothing to do for the  
ConnectedComponentImageFilter.

I'm not sure to understand how the spacing can have an impact on the  
performance of those filters - by definition, they are working on the  
neighbors of the pixels. Resampling the image shouldn't have much  
effect on the result, but will certainly have a quite bad effect on  
the execution time, and on the required memory!

Gaëtan


Le 15 nov. 09 à 16:48, Luis Ibanez a écrit :

> Hi Baoyun,
>
> The two filters:
>
> * itk::ConnectedComponentImageFilter     and
> * itk::BinaryDilateImageFilter
>
>
> Operate in Voxel (pixel) space.
>
> They DO NOT take the image spacing into account.
>
>
> You may want to resample you image off spacings:
>
>      0x6 x 0.6 x 2.5 mm
>
> into an isotropic image with spacing
>
>      0x x 0.6 x 0.6333
>
> (e.g. splitting Z slices into three).
>
> In this way, the operations of the Connectivity and Morphology
> filters will be closer to the intuitive expectations.
>
>
>      Regards,
>
>
>           Luis
>
>
> -----------------------
> On Fri, Nov 13, 2009 at 2:38 PM, Baoyun Li <baoyun_li123 at yahoo.com>  
> wrote:
>> Dear All:
>>
>> Can somebody tell me whetehr itkConnectedComponentImageFilter and
>> itkBinaryDilateImageFilter are operated on the physical space or  
>> voxel
>> space.
>> I have 0.6mmx0.6mmx2.5 mm ct data and want to do some morphorlogical
>> operation.
>>
>> I think the performance will be affected if the morphorlogical  
>> operation is
>> done on voxel space.
>>
>> So please guid me wheter those filters are operated on physical  
>> space? If
>> not, what should I do.
>>
>>
>> Thanks
>>
>> Baoyun
>>
>> _____________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Kitware offers ITK Training Courses, for more information visit:
>> http://www.kitware.com/products/protraining.html
>>
>> Please keep messages on-topic and check the ITK FAQ at:
>> http://www.itk.org/Wiki/ITK_FAQ
>>
>> Follow this link to subscribe/unsubscribe:
>> http://www.itk.org/mailman/listinfo/insight-users
>>
>>
> _____________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Kitware offers ITK Training Courses, for more information visit:
> http://www.kitware.com/products/protraining.html
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-users

-- 
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.itk.org
http://www.mandriva.org  http://www.bepo.fr

-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 203 bytes
Desc: Ceci est une signature ?lectronique PGP
URL: <http://www.itk.org/pipermail/insight-users/attachments/20091116/e09f120d/attachment.pgp>