[Insight-users] Re: ComputOffset in the class CenteredAffineTransform

[Luis Ibanez]

Hi Shuzai,


1) Thanks for letting us know about the ITK version that you are using.

2) Yes, just use the AffineTransform.
    The software guide matches ITK 2.4, that's why it says
    that you should call ComputeOffset(). This however, is no
    longer necessary, particularly not in ITK 3.2.

3) No, don't call ComputeOffset(), you shouldn't need to do it anymore.

4) If what you need is to cut the image in an arbitrary plane,
    you could use the VersorRigid3DTransform, the Euler3DTransform.
    or the Quaternion Transform., Unless, of course, you need to do
    any anisotropic scaling and/or shearing.


   Regards,


     Luis


------------------
Shuzai Fan wrote:
> Dear Luis,
> 
> Sorry for my late response, actually I just notice your reply. This 
> problem still bothers me at this time.
> 
> (1) I am using the latest version of ITK Release 3.2.0 (March 11 2007)
> 
> (2) You mean to useCenteredAffineTransform, there is no need to call 
> ComputeOffset? The ITK document still emphasizes that it is necessary to 
> call it.
> 
> (3) I will try itk::AffineTransform, but this method also has 
> ComputeOffset, do I need to call it?
> 
> Besides, what I really need to do is to cut the 3D image  using a 2D 
> plane (with arbitrary orientation and location) and get the pixels on 
> the cross-section.
> If you know a better way to do it using ITK, please let me know.
> 
> I am really appreciate all the help and time you spent on this.
> 
> Best wishes,
> 
> 
> Shuzai
> 
> ----------------------------------------------------------------------------------------- 
> 
> Luis wrote:
> 
> Hi Shuzai
> 
> 1) What version of ITK are you using ?
> 
> 2) You shouldn't need to call ComputeOffset()
> 
>     in a modern version of ITK.
> 
> 3) You shouldn't use the CenteredAffineTransform()
>     in a modern version of ITK (e.g. ITK > 3.0)
>     since now the standard itk::AffineTransform
>     also incorporates a SetCenter() method.
> 
> 
> Regards,
> 
>      Luis
> 
>