[Insight-users] image orientation and registration, current status ?

[Stefan Klein]

Hi,

Jeroen: the Origin IS taken into account. The Direction indeed not. I agree 
with it that this should be emphasised somewhere in the documentation. It's 
very easy to make a mistake with that.

Kind regards,
Stefan.



At 10:02 1-2-2008, J.S.Wijnhout at lumc.nl wrote:

>Hi,
>
>
>
>I have faced (or am facing actually) the same problem. I found it 
>espacially confusing that the itk::Image has a GetDirection and GetOrigin 
>method, however these are apparently not used in the 
>TransformContinuousIndexToPhysicalPoint method. If you want that, you 
>should use the itk::OrientedImage. But be warned, in the calculation of 
>the metric the orientation is ignored while computing the gradient. I 
>concluded that it is best to resample your image such that both images, 
>fixed and moving, have the same orientation. It is a bit cumbersome, but 
>it works and the results should not be too different from the results you 
>would get if the registration would properly using the image orientation. 
>Still I would like that orientation and origin are consistently used 
>within ITK (at the very least this behavior should  be properly documented!).
>
>
>
>best,
>
>Jeroen
>
>
>
>From: insight-users-bounces+j.s.wijnhout=lumc.nl at itk.org 
>[mailto:insight-users-bounces+j.s.wijnhout=lumc.nl at itk.org] On Behalf Of 
>Thees, Sebastian
>Sent: Friday, February 01, 2008 9:50 AM
>To: insight-users at itk.org
>Subject: [Insight-users] image orientation and registration, current status ?
>
>
>
>Dear itk developer,
>
>
>
>I am a new user of itk - so first at all, thanks for this fantastic 
>library and for providing it open source ! I was really surprised to found 
>such a comprehensive tool for image registration (and segmentation of 
>course) on the web.
>
>
>
>However, from the medical-image-analysis point of view, there is one thing 
>I could absolutely not understood. Why do you ignore image orientation in 
>image registration ?!?!? It so extremely limits the easy use of the 
>toolkit. Even an option to use the orientation cosines should be present.
>
>
>
>My question: Is there an example implementation of  the solution outlined 
>in http://public.kitware.com/Bug/view.php?id=5081 by Luis Ibanez, so that 
>I can continue with that for other metrics ? Or does a patch exsists ? 
>Hints, code snippets (i am not too much familiar with itk and template 
>techniques), etc are welcome ...
>
>
>
>best regards,
>
>Sebastian
>
>
>_______________________________________________
>Insight-users mailing list
>Insight-users at itk.org
>http://www.itk.org/mailman/listinfo/insight-users