<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>Dear Gaetan:</DIV>
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<DIV>Claiming structur element as [3 3 1] seems to be a simple solution.</DIV>
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<DIV>What I am wondering is how about if I only want to dilate or erod one voxel with slice? How to give teh structure elements in this case. Can I give structure elements as [1 1 0.33]? Seem the way you suggested has to do dilation with slice with 3 voxel.</DIV>
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<DIV>Is that true:</DIV>
<DIV>thanks</DIV>
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<DIV>Baoyun<BR></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Gaëtan Lehmann <gaetan.lehmann@jouy.inra.fr><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Baoyun Li <baoyun_li123@yahoo.com>; Luis Ibanez <luis.ibanez@kitware.com><BR><B><SPAN style="FONT-WEIGHT: bold">Cc:</SPAN></B> ITK Users <insight-users@itk.org><BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Mon, November 16, 2009 9:20:19 AM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [Insight-users] are itkConnectedComponentImageFilter and itkBinaryDilateImageFilter<BR></FONT><BR><BR>Hi,<BR><BR>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.<BR><BR>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!<BR><BR>Gaëtan<BR><BR><BR>Le 15 nov. 09 à 16:48, Luis Ibanez a écrit :<BR><BR>> Hi Baoyun,<BR>> <BR>> The two filters:<BR>> <BR>> * itk::ConnectedComponentImageFilter and<BR>> * itk::BinaryDilateImageFilter<BR>> <BR>> <BR>> Operate in Voxel (pixel) space.<BR>> <BR>> They DO NOT take the image spacing into account.<BR>> <BR>> <BR>> You may want to resample you image off spacings:<BR>> <BR>> 0x6 x 0.6 x 2.5 mm<BR>> <BR>> into an isotropic image with spacing<BR>> <BR>> 0x x 0.6 x 0.6333<BR>> <BR>> (e.g. splitting Z slices into three).<BR>> <BR>> In this way, the operations of the
Connectivity and Morphology<BR>> filters will be closer to the intuitive expectations.<BR>> <BR>> <BR>> Regards,<BR>> <BR>> <BR>> Luis<BR>> <BR>> <BR>> -----------------------<BR>> On Fri, Nov 13, 2009 at 2:38 PM, Baoyun Li <<A href="mailto:baoyun_li123@yahoo.com" ymailto="mailto:baoyun_li123@yahoo.com">baoyun_li123@yahoo.com</A>> wrote:<BR>>> Dear All:<BR>>> <BR>>> Can somebody tell me whetehr itkConnectedComponentImageFilter and<BR>>> itkBinaryDilateImageFilter are operated on the physical space or voxel<BR>>> space.<BR>>> I have 0.6mmx0.6mmx2.5 mm ct data and want to do some morphorlogical<BR>>> operation.<BR>>> <BR>>> I think the performance will be affected if the morphorlogical operation is<BR>>> done on voxel space.<BR>>> <BR>>> So please guid me wheter those filters are operated on
physical space? If<BR>>> not, what should I do.<BR>>> <BR>>> <BR>>> Thanks<BR>>> <BR>>> Baoyun<BR>>> <BR>>> _____________________________________<BR>>> Powered by <A href="http://www.kitware.com/" target=_blank>www.kitware.com</A><BR>>> <BR>>> Visit other Kitware open-source projects at<BR>>> http://www.kitware.com/opensource/opensource.html<BR>>> <BR>>> Kitware offers ITK Training Courses, for more information visit:<BR>>> http://www.kitware.com/products/protraining.html<BR>>> <BR>>> Please keep messages on-topic and check the ITK FAQ at:<BR>>> http://www.itk.org/Wiki/ITK_FAQ<BR>>> <BR>>> Follow this link to subscribe/unsubscribe:<BR>>> http://www.itk.org/mailman/listinfo/insight-users<BR>>> <BR>>> <BR>> _____________________________________<BR>> Powered by www.kitware.com<BR>> <BR>> Visit other Kitware
open-source projects at<BR>> <A href="http://www.kitware.com/opensource/opensource.html" target=_blank>http://www.kitware.com/opensource/opensource.html</A><BR>> <BR>> Kitware offers ITK Training Courses, for more information visit:<BR>> <A href="http://www.kitware.com/products/protraining.html" target=_blank>http://www.kitware.com/products/protraining.html</A><BR>> <BR>> Please keep messages on-topic and check the ITK FAQ at:<BR>> <A href="http://www.itk.org/Wiki/ITK_FAQ" target=_blank>http://www.itk.org/Wiki/ITK_FAQ</A><BR>> <BR>> Follow this link to subscribe/unsubscribe:<BR>> <A href="http://www.itk.org/mailman/listinfo/insight-users" target=_blank>http://www.itk.org/mailman/listinfo/insight-users</A><BR><BR>--Gaëtan Lehmann<BR>Biologie du Développement et de la Reproduction<BR>INRA de Jouy-en-Josas (France)<BR>tel: +33 1 34 65 29 66 fax: 01 34 65 29 09<BR>http://voxel.jouy.inra.fr
http://www.itk.org<BR>http://www.mandriva.org http://www.bepo.fr<BR><BR></DIV></DIV><!-- cg2.c4.mail.gq1.yahoo.com compressed/chunked Fri Nov 13 11:32:15 PST 2009 --></div><br>
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