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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Thanks for the information.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>To keep it simple I want to project forward a single slice which I load as a DICOM file.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Now I want to compute the sinogram of that slice and write it in a new file.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>I got a little confused about the ConstantImageSource which is used in the test class. Do I need it to compute a sinogram or is just a replacement of a itk::Image?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Here is my code so far:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> </span><span style='font-size:9.5pt;font-family:Consolas'>const unsigned int Dimension = 2;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> typedef float PixelType;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas'> </span><span lang=DE style='font-size:9.5pt;font-family:Consolas'>typedef itk::Image< PixelType, Dimension > ImageType;</span><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p></o:p></span></p><p class=MsoNormal><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'> …<o:p></o:p></span></p><p class=MsoNormal><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'> </span><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>(reading image by itk::ImageFileReader which works)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> …<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> ImageType::Pointer inputImage = reader->GetOutput();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> const unsigned int NumberOfProjectionImages = 1;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> ImageType::Pointer outputImage = ImageType::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> typedef rtk::JosephForwardProjectionImageFilter<ImageType, ImageType> ForwardType;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> ForwardType::Pointer forward = ForwardType::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> forward->SetInput(1, inputImage);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> forward->SetInput(0, outputImage);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> forward->Update();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> …<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> (writing output image into a file)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> …<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>The problem is that I get some errors when I instantiate the forward-Filter.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>The errors are like that one:<o:p></o:p></span></p><p class=MsoNormal><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'>error C2784: "vnl_matrix<T> operator *(const vnl_diag_matrix<T> &,const vnl_matrix<T> &)": template-Argument für "const vnl_diag_matrix<T> &" konnte nicht von "vnl_matrix_fixed<T,4,4>" hergeleitet werden.<o:p></o:p></span></p><p class=MsoNormal><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Maybe there is something wrong with the PixelType that i used?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>If the forward projection works, which filter should i use to achieve a filtered back projection without aliasing?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Many thanks in advance.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Tobias<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Von:</span></b><span lang=DE style='font-size:11.0pt;font-family:"Calibri",sans-serif'> simon.rit@gmail.com [mailto:simon.rit@gmail.com] <b>Im Auftrag von </b>Simon Rit<br><b>Gesendet:</b> Mittwoch, 4. Mai 2016 09:02<br><b>An:</b> Tobias Stein <tstein@stud.hs-heilbronn.de><br><b>Cc:</b> rtk-users@public.kitware.com<br><b>Betreff:</b> Re: [Rtk-users] forward and back projection - MITK<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><div><div><div><div><div><div><div><div><p class=MsoNormal>Dear Tobias,<o:p></o:p></p></div><p class=MsoNormal>The forward projection has 2 inputs:<o:p></o:p></p></div><p class=MsoNormal>- input 0: the stack of projections in which you wish to forward project,<o:p></o:p></p></div><p class=MsoNormal>- input 1: the volume you wish to forward project.<o:p></o:p></p></div><p class=MsoNormal>For the backprojection, it's exactly the same:<o:p></o:p></p></div><p class=MsoNormal>- input 0: the volume in which you wish to backproject,<o:p></o:p></p></div><p class=MsoNormal>- input 1: the stack of projections you wish to backproject.<o:p></o:p></p></div><p class=MsoNormal>Be aware that JosephBackProjectionImageFilter is the transpose of the forward projection and will have some aliasing (see, e.g., <a href="http://iopscience.iop.org/article/10.1088/0031-9155/49/11/024/meta;jsessionid=87B598ABFDC2AA07D1DED2DEE607F0E7.c2.iopscience.cld.iop.org">De Man and Basu</a> to see what I mean).<o:p></o:p></p></div><p class=MsoNormal>I have personally never used MITK but don't hesitate to share your experience on the mailing list.<o:p></o:p></p></div><p class=MsoNormal>Simon<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Wed, May 4, 2016 at 12:59 AM, Tobias Stein <<a href="mailto:tstein@stud.hs-heilbronn.de" target="_blank">tstein@stud.hs-heilbronn.de</a>> wrote:<o:p></o:p></p><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Hi all,<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>i want to use the forward and backward projection to reduce metal artefacts in ct images. I’ve seen so far that I may use the JosephForwardProjectionImageFilter to perform the forward projection. I’ve also seen the test for this class but I don’t get it, where should i put my 2D slice as input to execute the transformation. About the back transformation with the JosephBackProjectionImageFilter I also need more information how I can use it to transform a sinogram back to a ct slice. There is a test at the documentation, but the link is missing there.<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I’ve got another independent question.<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Are some of you familiar with MITK and know how to get the superbuild up and running with RTK? I am writing a MITK-Plugin and want to reduce the metal artifacts before a segmentation. So if some of you have experience with the combination of RTK and MITK it would be nice if you will share it ;)<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Best regards,<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Tobias<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=DE> <o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br>_______________________________________________<br>Rtk-users mailing list<br><a href="mailto:Rtk-users@public.kitware.com">Rtk-users@public.kitware.com</a><br><a href="http://public.kitware.com/mailman/listinfo/rtk-users" target="_blank">http://public.kitware.com/mailman/listinfo/rtk-users</a><o:p></o:p></p></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>