[Insight-developers] ImageSpatialObject Bug0006340

[Rupert Brooks]

Hi Folks,

I've been looking at the problem described here, and i think I've fixed it.
http://public.kitware.com/Bug/view.php?id=0006340

Briefly, the image spatial object takes the coordinate transform from
the image that it is given, and uses that as its IndexToWorld
transformation.  Previously, it was ignoring the direction.  The fix
was a matter of adding the necessary lines to copy the direction
information also.

However, this fix raises a further issue, and I'd like advice:

The itk::Image class may have a non-identity direction component, but
it always ignores it.  However, a naive implementation of my fix would
use that direction information, giving a different behavior than the
itk::Image.  I could write code to check if its an ITK image, and then
behave differently, but this seems inelegant at best.   Is this
actually another bug - should an itk::Image always have an identity
direction, to conform with its behavior?  Can i ignore the issue,
assuming the user will be bright enough to only put direction
information in an itk::Image for a very good reason.

That matter aside - let me know whether or not i should submit the
patch and new test(s).  I know we are going for a green dashboard for
the ITK3.8 release, and maybe i should wait until after.

Cheers,
Rupert


-- 
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Rupert Brooks
McGill Centre for Intelligent Machines (www.cim.mcgill.ca)
Ph.D Student, Electrical and Computer Engineering
http://www.cyberus.ca/~rbrooks