HI Simon thanks a lot for suggestion .
this helped me a lot Artefact have been removed so much Thank you very much for your reply Simon Rit <simon....@creatis.insa-lyon.fr> 於 2023年1月13日 週五 下午5:05寫道： > Hi, > So this is the same thing for the projections, you probably want to center > them and set origin to (1152-1)*0.25*-0.5=-143.875. This can be set with > reader->SetOrigin. The third coordinate of the origin vector is not used > in the projections images, you can leave it at 0. > Next is the angular arc. It is less than 360°. You will need to use the > Parker short scan weighting to reduce these artefacts, see here > <https://github.com/SimonRit/RTK/blob/master/applications/rtkfdk/rtkfdk.cxx#L100-L115> > a code example in C++. > Best regards, > Simon > > On Fri, Jan 13, 2023 at 9:30 AM 何明哲 <m10512...@yuntech.org.tw> wrote: > >> Hi Simon >> >> Sure, here is those information for reader->Getoutput() >> >> Size(XYZ)-> 1152,1152,270 >> Spacing(XYZ)-> 0.25,025,0.25. >> Origin(XYZ)-> 143.875,143.875,143.875 >> >> but your suggestion inspires me a lot , >> >> I was use add TiffimageIO to set size spacing origin to projectionreader >> source >> >> finally ,I can get this (see attached file ) >> >> Although the image still has a lot of artifact and is not clear enough, >> >> Did you have any suggestion for this? >> >> but finally it is a huge breakthrough for me >> >> thanks for help and reply again >> >> >> >> >> Simon Rit <simon....@creatis.insa-lyon.fr> 於 2023年1月12日 週四 下午10:57寫道： >> >>> Can you provide the size, origin and spacing of reader->GetOutput()? >>> It's a bit hard to help you without this information. >>> Simon >>> >>> On Thu, Jan 12, 2023 at 11:01 AM 何明哲 <m10512...@yuntech.org.tw> wrote: >>> >>>> >>>> Dear Simon >>>> >>>> Thanks for your reply .Its great help for me! >>>> >>>> 1.)I was refer your suggestion and modified the code, >>>> but the result will be a large blank area and I don't understand why >>>> >>>> here is the code and result >>>> >>>> sizeOutput[0] = Imagewidth; >>>> sizeOutput[1] = 1; >>>> sizeOutput[2] = numberOfProjections; >>>> spacing[0] = 0.25; >>>> spacing[1] = 0.25; >>>> spacing[2] = 0.25; >>>> origin[0] = (Imagewidth-1)*0.5*spacing[0]; >>>> origin[1] = (Imageheigh-1)*0.5*spacing[1]; >>>> origin[2] = spacing[2]*SliceN*-1; >>>> >>>> recoVolume->SetSize(sizeOutput); >>>> recoVolume->SetSpacing(spacing); >>>> recoVolume->SetOrigin(origin); >>>> recoVolume->SetConstant(0.); >>>> >>>> >>>> >>>> 2.)if you're doing 2D reconstruction, be careful that your projections >>>> should not be 1D because the backprojection uses a 2D interpolation. It >>>> should have at least 2 lines. >>>> --> Yes , I hope I can eventually reconstruct a 2D CT Slice, if my >>>> read projection step or setting have any problem please let me know, >>>> >>>> thanks for your reply >>>> >>>> BR, >>>> >>>> >>>> >>>> >>>> >>>> Simon Rit <simon....@creatis.insa-lyon.fr> 於 2023年1月12日 週四 下午4:30寫道： >>>> >>>>> Hi, >>>>> I'm not sure I have enough information to answer... What I can say is: >>>>> - that the origin is not set to center your volume, for centering, you >>>>> should use (size-1)*0.5*spacing >>>>> - if you're doing 2D reconstruction, be careful that your projections >>>>> should not be 1D because the backprojection uses a 2D interpolation. It >>>>> should have at least 2 lines. >>>>> I hope it helps, >>>>> Simon >>>>> >>>>> On Thu, Jan 12, 2023 at 8:46 AM 何明哲 <m10512...@yuntech.org.tw> wrote: >>>>> >>>>>> >>>>>> HI Everyone , >>>>>> >>>>>> I have a question >>>>>> that When I was refer to the official example >>>>>> "Firstcudareconstruction.cpp", >>>>>> then I tried to modify the code and reconstruction 2D x ray >>>>>> projection image to 2D ct slice, >>>>>> the code is worked but I got the wrong result too, >>>>>> I don't understand what the problem I'm have ? >>>>>> it's possible that the setting of reconstruction output image size >>>>>> or origin is wrong? >>>>>> >>>>>> here is my code and result (I was tried to only reconstruction just >>>>>> a slice NO.100 of the whole volume) >>>>>> >>>>>> >>>>>> -------------------------------------------------------------------------------------------- >>>>>> using GeometryType = rtk::ThreeDCircularProjectionGeometry; >>>>>> GeometryType::Pointer geometry = GeometryType::New(); >>>>>> unsigned int numberOfProjections = 280; >>>>>> double firstAngle = 0; >>>>>> double angularArc = 280; >>>>>> unsigned int sid = 510; >>>>>> unsigned int sdd = 690; >>>>>> >>>>>> for (unsigned int noProj = 0; noProj < numberOfProjections; >>>>>> noProj++) >>>>>> { >>>>>> double angle = firstAngle + noProj * angularArc / >>>>>> numberOfProjections; >>>>>> geometry->AddProjection(sid, sdd, angle); >>>>>> } >>>>>> >>>>>> rtk::ThreeDCircularProjectionGeometryXMLFileWriter::Pointer >>>>>> xmlWriter; >>>>>> xmlWriter = >>>>>> rtk::ThreeDCircularProjectionGeometryXMLFileWriter::New(); >>>>>> xmlWriter->SetFilename(".\\RTK_Geometry.xml"); >>>>>> xmlWriter->SetObject(geometry); >>>>>> xmlWriter->WriteFile(); >>>>>> >>>>>> using NameGeneratorType = itk::NumericSeriesFileNames; >>>>>> NameGeneratorType::Pointer nameGenerator = NameGeneratorType::New(); >>>>>> >>>>>> nameGenerator->SetSeriesFormat(ProjectionInage +"\\%d.tif"); >>>>>> nameGenerator->SetStartIndex(1); >>>>>> nameGenerator->SetEndIndex(280); >>>>>> nameGenerator->SetIncrementIndex(1); >>>>>> >>>>>> using IutputImageType = itk::CudaImage<float, 3>; >>>>>> using ReaderType = rtk::ProjectionsReader<IutputImageType>; >>>>>> ReaderType::Pointer reader = ReaderType::New(); >>>>>> reader->SetFileNames(nameGenerator->GetFileNames()); >>>>>> reader->Update(); >>>>>> >>>>>> using ConstantImageSourceType = >>>>>> rtk::ConstantImageSource<OutputImageType>; >>>>>> ConstantImageSourceType::PointType origin; >>>>>> ConstantImageSourceType::SpacingType spacing; >>>>>> ConstantImageSourceType::SizeType sizeOutput; >>>>>> ConstantImageSourceType::Pointer recoVolume = >>>>>> ConstantImageSourceType::New(); >>>>>> >>>>>> sizeOutput[0] = Imagewidth; >>>>>> sizeOutput[1] = Imageheigh; >>>>>> sizeOutput[2] = numofproj; >>>>>> spacing[0] = 0.25; >>>>>> spacing[1] = 0.25; >>>>>> spacing[2] = 0.25; >>>>>> origin[0] = Imagewidth*spacing[0]*0.5*-1; >>>>>> origin[1] = Imageheigh*spacing[0]*0.5*-1; >>>>>> origin[2] = spacing[2]*SliceN*-1; >>>>>> >>>>>> recoVolume->SetSize(sizeOutput); >>>>>> recoVolume->SetSpacing(spacing); >>>>>> recoVolume->SetOrigin(origin); >>>>>> recoVolume->SetConstant(0); >>>>>> >>>>>> using FDKGPUType = rtk::CudaFDKConeBeamReconstructionFilter; >>>>>> FDKGPUType::Pointer feldkamp = FDKGPUType::New(); >>>>>> >>>>>> feldkamp->SetInput(0, recoVolume->GetOutput()); >>>>>> feldkamp->SetInput(1, reader->GetOutput()); >>>>>> feldkamp->SetGeometry(geometry); >>>>>> feldkamp->SetNumberOfThreads(7); >>>>>> feldkamp->Update(); >>>>>> >>>>>> using WriterType = itk::ImageFileWriter<OutputImageType>; >>>>>> WriterType::Pointer writer = WriterType::New(); >>>>>> writer->SetFileName("C:\\RTK.mhd"); >>>>>> writer->SetInput(feldkamp->GetOutput()); >>>>>> writer->Update(); >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> it should be look like this >>>>>> >>>>>> >>>>>> thanks for your reply >>>>>> >>>>>> BR, >>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Rtk-users mailing list >>>>>> rtk-us...@openrtk.org >>>>>> https://www.creatis.insa-lyon.fr/mailman/listinfo/rtk-users >>>>>> >>>>>
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