[Insight-users] coordinate system

[WANG Chengjia]

More generally, I have a transformation matrix calculated, anyone know how
to transform a volume using this matrix?

It is just a simple Rigid 3D transformation. In Matlab, I just use "tform =
maketform('affine', transM');" to make up the transformation and apply it
using " tformarray " then the images are perfectly aligned. But in ITK, I
find I have to switch the x, y coordinate of translation when doing
"targetTransform->SetTranslation(trans)". The result was still wrong,
although quite close to the one I got in Matlab.

Can anyone help? Thanks in advance!

Best,



On Tue, Feb 18, 2014 at 7:39 PM, WANG Chengjia
<wangchengjia1986 at gmail.com>wrote:

> Hello,
>
> I'm now working on a machine learning based 3D image registration work. To
> create the ground truth registration, I need to firstly using simple least
> square method to calculate a transformation from the corresponding point
> (I'm using RIRE datasets).
>
> The same working flow in matlab and itk produced the same transformation
> matrix, but different transformed volume! In matlab, it's well aligned
> using the coordinates of control points given by RIRE dataset. But in ITK I
> have to inverse and switch the translation parameters. Then I realized it's
> because of the different coordinate system in itk and Matlab.
>
> Can anyone tell me a method to convert transformation matrix calculated
> from the common coordinate system into the ITK one?
>
> Thank you very much!
>
> Best,
>
> --
> Chengjia Wang
> Phd Student,
> University of Edinburgh
> Clinical Research Imaging Center (CRIC)
> Toshiba Medical Visualization Systems Europe, Ltd
> Email: wangchengjia1986 at gmail.com
>



-- 
Chengjia Wang
Phd Student,
University of Edinburgh
Clinical Research Imaging Center (CRIC)
Toshiba Medical Visualization Systems Europe, Ltd
Email: wangchengjia1986 at gmail.com
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