[IGSTK-Users] Get dimensions from igstkImageSpatialObject

[Luis Ibanez]

Hi Torleif,

We are trying to replicate the problem that you reported
regarding the window leveling of hte ImageSpatialObject.

The issue has been logged as bug #5528:
   http://public.kitware.com/Bug/view.php?id=5528

In order to track the problem we added a specific test
for window leveling:

   IGSTK/Testing/
   igstkCTImageSpatialObjectRepresentationWindowLevelTest.cxx

This test loads the DICOM CT image in Testing/Data/Input/E000192

and goes through a series of Levels, for a given window.

The behavior that we observe seems to be consistent with
what we were expecting.

Could you share with us the MR image that is producing the
effect that you described ?

We would like to try it with this test, and compare the
window levels to what we can see in VolView.


    Please let us know,


      Thanks



         Luis


-------------------------
Torleif Sandnes wrote:
> Thanks for your reply.
> 
>> If you are doing volume rendering, that functionality will presumably
>> be implemented in an igstk::ImageSpatialObjectRepresentation class.
> 
> 
> Well, I will probably have to inherit from igstkSpatialObject and  
> mirror some functionality from ImageSpatialObject. None of the  methods 
> in igstkImageSpatialObject is virtual.
> 
>>    Inside this class, you can have access to the vtkImageData.
>>
>> We should not expose image information outside of IGSTK components.
> 
> 
> AFAICS, RequestGetItkImage() and RequestGetVtkImage() is public in  
> igstkimageSpatialObject.
> (http://public.kitware.com/IGSTK/NightlyDoc/ 
> classigstk_1_1ImageSpatialObject.html)
> So, I would probably be able to do this outside of IGSTK if I really  
> wanted to?
> 
>> Do you have your volume rendering class in the IGSTK Sandbox ?
> 
> No, I am just using a modified version of the  
> igstkImageSpatialObjectVolumeRepresentation from the DeckOfCardRobot  
> example.
> 
>> We could guide you on how to gain access to the vtkImageData,
>> and still remain inside the IGSTK walls. The process should be
>> very similar (if not identical) to what is done in the file
>>
>>    igstkImageSpatialObjectRepresentation.txx
> 
> 
> True, I had a look and I think I should be able to get access to what  I 
> wanted.
> 
> Btw, looking through the igstkImageSpatialObjectRepresentation class,  I 
> see that all images are converted to unsigned char because of a  
> restriction in vtkImageActor. Next, a vtkImageMapToColors is used to  
> set window width and level. Could it be something here that results  in 
> the problems we have getting good representation of MR images? CT  
> images are looking good. ( Attached a screenshot. igstk application  to 
> the left, osirix to the right. Window level 1011, window width:  2319 in 
> both applications.)
> 
> Regards,
> 
> Torleif
> 
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