[Insight-users] use of transform with itk volume

[Luis Ibanez]

Hi Jorn,

It shouldn't be necessary to use the
ChangeInformationImageFilter on the
registration framework.

What is the type of transform that is
recovered from the image file ?

Is it like an Affine transform ?

Are the spacing and origin of the images
specified independently or are they
included in the transform ?


I would suggest you to read the images
from the files and if the spacing and origin
are specified independently of the transform,
make sure that they are passed consistenlty
to the itkImage.

You can use the itk::Image methods

     SetOrigin()
     SetSpacing()

please take a look at the example:

Insight/Examples/DataRepresentation/Image/

           Image4.cxx

---

Then, use the transform from the file to
initialize an itkAffineTransform and get
its parameters using GetParameters(). Then
use this parameters as the initial guess of
the registration method. This is done by
passing the parameters array to the
SetInitialParameters() method of the
registration method class.

In that way, the registration will start
by applying the transform specified in
your file.

Note that once the registration is done,
the resulting transformation will include
the transform that you set up in the
initial parameters.


Please let us know if you have further
questions,



   Thanks,


    Luis


=============================

J. Van Dalen wrote:

> Hi Luis,
> 
> Thanks for your answer. It clarifies a lot.
> 
> You mention that: 
> 
>>The registration methods will only use the space an origin
>>in your image. Not the full transform.
>>
> 
> I.e., should I use the ChangeInformationImageFilter for setting the space
> and origin?
> 
> Thanks,
> Jorn.
> 
> 
>