<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><div>Hi Simon, <br></div><div><br></div><div>you are right, it works now. Thanks for your reactivity. <br></div><div><br></div><hr id="zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>De: </b>"Simon Rit" <simon.rit@creatis.insa-lyon.fr><br><b>À: </b>"Mathieu DUPONT" <mdupont@cppm.in2p3.fr><br><b>Cc: </b>rtk-users@public.kitware.com<br><b>Envoyé: </b>Lundi 9 Février 2015 15:08:12<br><b>Objet: </b>Re: [Rtk-users] fdk artefact, sourceOffsetY<br><div><br></div><div dir="ltr"><div>Hi Mathieu,<br>Thanks for the observation. The truth is that we haven't tested thoroughly this kind of geometry because I generally prefer to keep the source in the central plane... Still, I have looked into the artifact that you pointed out, which is only visible with a narrow window / level, and found the cause which was a bug. I think this will fix it:<br><a href="https://github.com/SimonRit/RTK/commit/b0dd88821b751671d32ef0fa2f1ff2ae85a4083c" target="_blank" data-mce-href="https://github.com/SimonRit/RTK/commit/b0dd88821b751671d32ef0fa2f1ff2ae85a4083c">https://github.com/SimonRit/RTK/commit/b0dd88821b751671d32ef0fa2f1ff2ae85a4083c</a><br></div>Indeed, this only concerns FBP reconstruction, SART and other iterative algorithms should not be impacted. Let us know if you observe some other surprising artifacts.<br>Thanks again,<br>Simon<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Feb 6, 2015 at 6:27 PM, Mathieu DUPONT <span dir="ltr"><<a href="mailto:mdupont@cppm.in2p3.fr" target="_blank" data-mce-href="mailto:mdupont@cppm.in2p3.fr">mdupont@cppm.in2p3.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex" data-mce-style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;">Hello rtk users,<br> <br> I try to use RTK for reconstruction in my lab but I encounter some problems.<br> <br> I try to reconstruct a simulated spheroid. I join my phantom text file (SheppLogan.txt).<br> <br> If I set source_y=0, I get a correct (I guess) reconstruction, see the joined figure1.png. I use the followind set of commands :<br> <br> rtksimulatedgeometry -n 180 --sdd=508.1658133423730 --sid=242.7169928585076 --proj_iso_x=-53.500206362627239 --proj_iso_y=-10.768620138555379 --source_y=0 -o geometry.xml && rtkprojectgeometricphantom -g geometry.xml -o /tmp/tmpfs/projections.mha --spacing 1 --dimension 512 --phantomfile SheppLogan.txt && rtkfdk -v -p /tmp/tmpfs/ -r projections.mha -o /tmp/tmpfs/fdk_ccd.mha -g geometry.xml --spacing 0.07 --origin -20,14,-20 --dimension 600,600,600 --hardware="cuda"<br> <br> But If I set source_y=15, I obtain some strange artefacts as you can see on figure2.png. Do you know the origin of this pattern (the vertical one) ? Is it normal ? Or my geometry is completely wrong ? If I use rtksart, this artefact doesn't exist.<br> <br> Thanks in advance and thanks for this nice toolkit.<br> <br> regards,<br> Mathieu Dupont<br> <br> <br> <br> <br> <br> <br>_______________________________________________<br> Rtk-users mailing list<br> <a href="mailto:Rtk-users@public.kitware.com" target="_blank" data-mce-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" data-mce-href="http://public.kitware.com/mailman/listinfo/rtk-users">http://public.kitware.com/mailman/listinfo/rtk-users</a><br> <br></blockquote></div><br></div></div><div><br></div></div></body></html>