[Insight-users] time of non rigid registation.

[Tao, Guozhi]

Hi, Luis:
Thanks for your reply. Can you further tell  me your impression that the time for Demons' algorithm and Rohlfing's  B spline based registration (3 mm control knots) seperately  to register  256*256*128  volume. More specicely, I like to know the ratio of regstration time for those two algorithm.
 
Best wishes
Guozhi 

________________________________

From: Luis Ibanez [mailto:luis.ibanez at kitware.com]
Sent: Thu 6/21/2007 6:01 PM
To: Tao, Guozhi 
Cc: Torsten Rohlfing; insight-users at itk.org
Subject: Re: [Insight-users] time of non rigid registation.




Hi Guozhi,

For that image size you should expect between 30min and 1hour.

Note, that the registration time depends on many factors,
including, how much actual misalignment there is originally
between the two images.


   Regards,


      Luis


---------------------
Tao, Guozhi wrote:
> Hi:
> Can sombody tell me how long the nonrigid registration algorithm in ITK need to register 256*256*128 volume on current pentium4 pc. I want to know the time consuming for Demons algorithm and BSplineDeformableTransform. Just roughtly estimation by your experience is fine.
> best wishes
> Guozhi Tao
> 
>
> ________________________________
>
> From: insight-users-bounces+guozhi.tao=uth.tmc.edu at itk.org on behalf of Torsten Rohlfing
> Sent: Thu 6/14/2007 11:15 AM
> To: insight-users at itk.org
> Subject: [Insight-users] a question about rigid + nonrigid registration
>
>
>
>
>>I am currently trying to register two volumes. One volume only contains part
>>of the other, so I used the larger volume as fixed image and smaller volume
>>as the moving image.  First, I performed a rigid
>>registration(VersorRigid3DTransform) and then want to fine tune the
>>rigistration by nonrigid method (BSplineDeformableTransform). However, I do
>>not know how to initialize the  BSplineDeformableTransform using the
>>existing rigid result (VersorRigid3DTransform). Maybe I can use resample
>>filter to get a new moving image based on the rigid registration. But the
>>resampled moving image has the size of the larger volume, so some voxels do
>>not have resampled value and this will cause problems in further nonrigid
>>registration. Hope I made my questions clear.
>>
>>Qing
>>
>
> Hi --
>
> Indeed, resampling the moving image after affine and before nonrigid
> registration is not a good idea, both for the reason you mentioned (loss
> of field of view boundaries) and because interpolation artifacts can
> build up from stage to stage.
>
> What you need to do is take your rigid transformation and set it as the
> "Bulk Transform" in the B-spline transformation object. That's all.
> Please consult the online documentation for the exact name of the member
> function in BSplineDeformableTransform.
>
> Best,
>   Torsten
>
> --
> Torsten Rohlfing, PhD          SRI International, Neuroscience Program
>  Research Scientist             333 Ravenswood Ave, Menlo Park, CA 94025
>   Phone: ++1 (650) 859-3379      Fax: ++1 (650) 859-2743
>    torsten at synapse.sri.com        http://www.stanford.edu/~rohlfing/
>
>      "Though this be madness, yet there is a method in't"
>
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>
>
> _______________________________________________
> Insight-users mailing list
> Insight-users at itk.org
> http://www.itk.org/mailman/listinfo/insight-users
>