[Rtk-users] Reconstruct from projections; Starter tips

[M Miller]

I'm new to RTK and I'd like to reconstruct some projections into a volume. So far I've only been able to get an "InvalidRequestedRegionError", but I'd like to describe my steps with the hope that someone can point out what I've done wrong.

I built RTK using VS2010 x64, ITK 3.20.1, and CUDA 4.2. The sample programs seem to work fine as I can successfully walk through the FDK SheppLogan example.

My projections are 3143 16-bit tif files, each 2000x2000 pixels in size, covering 360deg of rotation. The center of rotation is 65.93mm from the xray source, and the detector is 870.86mm from the source. The detector is 2000x2000 pixels in size, with each pixel 0.2mmx0.2mm in size.
 
I create a geometry file:
"rtksimulatedgeometry.exe --output=geo.xml --nproj=3143 --arc=360 --sdd=870.86 --sid=65.93"
 
Attempt to reconstruct:
"rtkfdk.exe --verbose --lowmem --geometry d:\ct_projections\geo.xml --path=d:\ct_projections\test\ --regexp=tif$ --output=d:\ct_projections\rtkfdk.mha --divisions=2"
 
Output:
>Regular expression matches 3143 file(s)
>Reading geometry information from d:\ct_projections\geo.xml...
>Reconstructing and writing... ExceptionObject caught with writer->Update()
>
>itk::InvalidRequestedRegionError (0000000000009FED10)
>Location: "void ___cdecl itk::DataObject::PropagateRequestedRegion(void) throw(class itk::InvalidRequestedRegionError)"
>File: ..\..\..\InsightToolkit-3.20.1\Code\Common\itkDataObject.cxx
>Line: 397
>Description: Requested region is (at least partially) outside the largest possible region.
 
I have replaced the original macro "TRY_AND_EXIT_ON_ITK_EXCEPTION( reader->Update() )" with just "reader->Update()", otherwise there is no debug information.

The "lowmem" switch is required to keep ITK from crashing, which I think is an unrelated problem. I use "divisions=2" because plastimatch would crash for me without specifying something similar. Setting the "hardware" switch to either cpu or cuda produces the same error. The client machine has 32 processors, 128GB RAM, Tesla C2070, and is running Win7 x64.
 
Is there any extra information necessary or anything that needs clarification?
How can I use RTK to reconstruct a volume, if possible?
 
Thanks
Micah
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