[Rtk-users] Issues using PhaseGatingImageFilter

[Geoff Hugo]

I’m trying to use the PhaseGatingImageFilter class to reconstruct a single breathing phase volume and am running into some problems.  I’ve incorporated this class into an application similar to rtkfdk, putting it in the pipeline between ParkerShortScanImageFilter and FDKConeBeamReconstructionFilter.  If I run the application trying to select a subset of projections using the method SetGatingWindowCenter, I get a segmentation fault.  The fault is occurring due to allocation errors in rtk::BackProjectionImageFilter::GenerateInputRequestedRegion.  It appears that since the geometry specific to the selected projections is selected in PhaseGatingImageFilter::GenerateData, there is a disconnect between the geometry size and projection stack size during GenerateInputRequestedRegion in the pipeline (pipeline OutputInformation shows the projection stack size is equal to the size of the selected breathing phase projections, but the geometry size is still the total number of (unsorted) projections).

I can workaround this problem by calling PhaseGatingImageFilter->Update(), but I think this will break the streaming functionality?  Any easy solutions to this problem that will preserve streaming and let me run the full pipeline with only one Update call?  My guess is I will need to move the geometry subselection to PhaseGatingImageFilter::GenerateOutputInformation() then call UpdateOutputInformation in the main application?

Thanks,
Geoff

------------------------------------
Geoffrey D. Hugo, Ph.D.
Associate Professor, Radiation Oncology
Director, Medical Physics Graduate Program
Virginia Commonwealth University
(804) 628 3457


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/rtk-users/attachments/20141031/2d40cc96/attachment-0008.html>