Thanks! I will try both the SIRT with 100 iterations and the conjugate gradient method. What exactly are the weights (input 2) and input support mask in rtkConjugateGradientConeBeamReconstructionFilter?
On 18-07-17 11:31, Cyril Mory wrote: > Hi Lotte, > > I had a very quick look at what you are doing. It looks fine to me, > you just need to perform way more iterations in the SIRT case. 100 > would be a good start. SIRT is more stable than SART when there are > inconsistencies in the projection data, but converges slowly. > > An alternative to SIRT, which minimizes the same cost function with a > faster algorithm, is the conjugate gradient algorithm. You should > obtain nice results with something like 30-40 iterations (look for > rtk::ConjugateGradientConeBeamReconstructionFilter if you want to give > it a try). > > Best regards, > Cyril > > > On 18/07/2017 11:17, Lotte Schyns wrote: >> Hello, >> >> We are having problems with the SIRT reconstructions. They seem very >> strange and blurry. However, other reconstructions (SART, FDK, >> iterativeFDK) look perfect. I uploaded an example of a SART and a SIRT >> reconstruction (same parameters) to >> https://www.dropbox.com/sh/7a4bkyjg43zjmy7/AAAp4tJrk9HedMEEuIKsGYDSa?dl=0. >> >> I also uploaded a minimalistic version of the code that I used (the >> paths in CMakeLists.txt probably need to be adapted to your system). You >> can alternate between SART and SIRT by changing line 143. The raw data >> is also available on dropbox. I didn't use >> rtkXRadRawToAttenuationImageFilter, because our projections are already >> corrected for the dark field and flood field, so >> (signal-dark)/(flood-dark). I just take the natural logarithm and >> multiply by -1. Do you know what could be the problem with the SIRT >> reconstructions? Are we using wrong parameters? Thanks for your time. >> >> Lotte >> _______________________________________________ >> Rtk-users mailing list >> Rtk-users@public.kitware.com >> http://public.kitware.com/mailman/listinfo/rtk-users > _______________________________________________ Rtk-users mailing list Rtk-users@public.kitware.com http://public.kitware.com/mailman/listinfo/rtk-users
