[Rtk-users] 答复: Rtk Detector Displacemets

[Simon Rit]

Dear Freyman li,
Have you solved your problem ? If not, my guess would be that you have not
set the origin of your projections correctly. Where does your calibration
assume the location of point (0,0) in your projections? Since you have very
small X projection offsets, it probably assumes that it's at the center of
the projection so you must set the origin, i.e., the coordinate of the
first pixel, at (0.5*0.254*767, 0.5*0.254*959). If you don't do that,
rtkfdk detects a large offset that it cannot correct for.
Simon

On Mon, Dec 14, 2015 at 6:32 AM, Freyman li <lihanwei_1500 at 126.com> wrote:

> Thanks for your help! I attached the geometry settings to this email. And
> my detector size is 768*960 with a pixel size 0.254mm.
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> *发件人:* louie L [mailto:ghostcz at hotmail.com]
> *发送时间:* 2015年12月14日 11:38
> *收件人:* Freyman li; rtk-users at public.kitware.com
> *主题:* RE: [Rtk-users] Rtk Detector Displacemets
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> Sent from Mail <http://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
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> *From: *louie L <ghostcz at hotmail.com>
> *Sent: *Monday, December 14, 2015 04:38
> *To: *Freyman li <lihanwei_1500 at 126.com>
> *Subject: *RE: [Rtk-users] Rtk Detector Displacemets
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> Hi,
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> Can you post your geometry file to the mail list? Your problem sounds like
> a result of wrong geometry settings.
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> Best regards,
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> Louie
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> Sent from Mail <http://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
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> *From: *Freyman li <lihanwei_1500 at 126.com>
> *Sent: *Monday, December 14, 2015 04:25
> *To: *Rtk-users at public.kitware.com
> *Cc: *rtk-users at openrtk.org
> *Subject: *[Rtk-users] Rtk Detector Displacemets
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> Dear rtk-users,
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> I have generated the geometry XML file by using the geometry calibration
> in my CBCT system. And I want to reconstruct the volume from 360 raw
> projections data.
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> But after running the rtkfdk.cxx, I get an output message that "Cannot
> account for too large detector displacements, a part of space must be
> covered by all projections."
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> And I try to use the addprojection function to generate a simple geometry
> structure using only SID and SDD, this problem did not happen but the
> reconstruction result is not correct.
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> How can I solve this problem? Is there any limitation about the detector
> weighting?
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> I really appreciate any help you can provide.
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> With regards,
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> Freyman li
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> _______________________________________________
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> http://public.kitware.com/mailman/listinfo/rtk-users
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