[Insight-users] registration question

[Luis Ibanez]

Hi Ken,

Thanks for your detailed email.

Your expectation is correct: doing a checker board
with the resample output moving image, should result
in an aligned image.

What Transform type are you using ?


BTW: If you were not using DICOM, I would have
suspected that your file format was dropping vital
information such as Origin or Orientation,... but
that shouldn't happen with DICOM.


Could you please add print for the output resampled
moving image just after you write it out with the series
reader ?

Something like

    resampler->GetOutput()->Print( std::cout );

then do the same for the fixed image.

(both of this from the Registration code).

Then add similar Print() statements on the code
that loads the two images and do the checker
board.

It is likely that you will find in this way that some
of the vital image grid information has been lost
from the registration program to the checker board
program.


      Regards,


            Luis


-----------------------------------------------------------------------
On Thu, May 13, 2010 at 11:37 PM, Ken Urish <ken.urish at gmail.com> wrote:
> I have the mattes multimodality registration working great. The
> checkerboard shows great alignment.
>
> However, when I take the output images from the registration (ie the
> moving images that are now aligned with teh fixed images) and do a
> checkerboard with the 'fixed' instead of getting identical output as
> the registration program its shifted by about 10 pixels and not
> aligned???? The code is heavily based on the mattes registration
> example.
>
>
> In the registration, the checkerboard is pulled from the same pipeline
> as the output images (immediately after resampling). In the 2nd
> program that overlays the output folder and the 'fxed' folder I simply
> put both straight into a checker board. I cant figure out why they are
> not aligning up?
>
> I attached code below.
>
>
> This is for the checkerboard::
>
> //----------------------------------------------------------------------------------
> // DICOM SERIES READER
> //----------------------------------------------------------------------------------
>  typedef itk::ImageSeriesReader< FixedImageType > FixedReaderType;
>  typedef itk::ImageSeriesReader< MovingImageType > MovingReaderType;
>  typedef itk::GDCMSeriesFileNames NamesGeneratorType;
>  typedef itk::GDCMImageIO  ImageIOType;
>
...snip...