[Insight-users] Re: gray scale erosion

[Luis Ibanez]

Hi Raghu,

Mathematical Morphology filters in ITK do not use
physical coordinates but pixel coordinates. The
radius of the structuring element is specified
in number of pixels.

This is traditional in Mathematical Morphology, and
should invite some reflexion on your part before
you apply such filters to any anisotropic data....


    Regards,


      Luis


------------------------------

raghu venkatram wrote:

> hello all,
> 
> I am using the mathematical morphology gray scale erosion filter to 
> shrink some volume of interest.
> 
> My pixels are isotrpic in x, y and z and are .125 mm. I was not sure if 
> in ITK the radius of the structuring element would let me specify the 
> amount of shrinking in x, y z, i would like 2mm in all 3 dimensions.
> 
>  
> 
> Thanks, in advance
> 
> Raghu
> 
> 
> 
>  
> 
>  >From: Luis Ibanez <luis.ibanez at kitware.com>
>  >To: raghu venkatram <raghu_420 at hotmail.com>
>  >CC: Insight-users at itk.org
>  >Subject: Re: [Insight-users] landmark initialized mutual 
> informationregistration
>  >Date: Tue, 27 Jul 2004 17:47:29 -0400
>  >
>  >
>  >Hi Raghu,
>  >
>  >What version of ITK are you using ?
>  >
>  >There was a bug fixed recently in this application,
>  >related to the number of parameters used in some
>  >Transforms.
>  >
>  >If you want to use this application, you probably
>  >want to use the CVS version.
>  >
>  >
>  >   Regards,
>  >
>  >
>  >      Luis
>  >
>  >
>  >
>  >--------------------------
>  >raghu venkatram wrote:
>  >
>  >>
>  >>Hi All,
>  >>
>  >>I am running the land mark initialized mutual information based
>  >>registration application.
>  >>I am trying to register an MR and a CT volume,
>  >>
>  >>MR volume: 256x256x74 (.89844 mm x .89844 x 2mm)
>  >>CT volume: 512 x 512x55 ( ..55469 x .55469 x 2mm) voxel sizes
>  >>
>  >>I get some strange runtime errors, while initializing with 4
>  >>landmark points.
>  >>below is the log with osme of my debugging echo statements. I also
>  >>get a Debug error MS VC++ error: Damage: after normal block #7071.
>  >>
>  >>I would be glad if somebody could give me some pointers or had
>  >>similar experiences.
>  >>
>  >>Thanks,
>  >>Raghu
>  >>
>  >>Registration begins.
>  >>Register using landmarks
>  >>fixed landmarks=4
>  >>moving landmarks=4
>  >>68.2813 105.117 72
>  >>111.406 63.7891 72
>  >>143.75 110.508 72
>  >>108.711 148.242 72
>  >>141.445 155.867 43.8203
>  >>115.375 127.023 43.8203
>  >>0 0 0
>  >>171.953 128.688 43.8203
>  >>centers
>  >>428.773 411.578 131.461
>  >>432.148 427.656 288
>  >>centers
>  >>107.193 102.895 32.8652
>  >>108.037 106.914 72
>  >>0 0 0
>  >>LandmarkRegistrator: InitialParameters =
>  >>[0, 0, 0, 107.193, 102.895, 32.8652]
>  >>-------------------------------------------------
>  >>Exception caught in LandmarkRegistrator:
>  >>unknown exception caught !!!
>  >>-------------------------------------------------
>  >>-------------------------------------------------
>  >>Exception caught in ImageRegistrationApp:
>  >>unknown exception caught !!!
>  >>-------------------------------------------------
>  >>DEBUG: Landmark registration FINAL centered versor transform:
>  >>[0, 0, 0, 0, 0, 0]
>  >>DEBUG: Landmark registration FINAL affine transform:
>  >>[1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0]
>  >>
>  >>_________________________________________________________________
>  >
>  >
>  >
>  >
>  >_______________________________________________
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>  >Insight-users at itk.org
>  >http://www.itk.org/mailman/listinfo/insight-users
> 
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