[Insight-developers] ImageSpatialObject Bug0006340

[Luis Ibanez]

Hi Rupert,


             Thanks for looking at this bug.


Given how close we are to the release, and given that it doesn't seem
to be a critical issue, let's wait 48 hours, until the release is over
and then you can experiment with the fix once we reopen the repository.

Please note that the first action to take, even before experimenting
with a fix, is to add a tests that illustrates the failure. E.g. to
add a test that exercise the condition you have identified as
problematic.


    Thanks for helping improve the toolkit,


        Luis


---------------------
Rupert Brooks wrote:
> 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
> 
>