[Insight-users] some information on the registration example methods

[Michael G]

Hi Luis,

Thank you for all the information - I've been trying different approaches as 
you suggested and they have resulted in reduced computation times.

I still have a question about the MultiResolutionPDEDeformableRegistration 
template.. In the MultiResolutionImageRegistrationMethod template there are 
methods to set the optimizer at the start time and through an observer. I 
can't figure out how to use an observer to 'push' the 
MultiResolutionPDEDeformableRegistration template in the right direction 
during registration - is it not possible, and the reason this method will be 
faster than using the pure DemonsRegistration is that you can set the number 
of levels and it will work on those? (instead of just the original) Are 
there any tweaks you can do to make it faster?

Lastly, while looking for other posts about registration I came across a 
series of posts having to do with itk::FixedArray<> and the itk::Array<> in 
regards to speeding up some registration methods. The posts were from last 
May, did anything come of it?
http://www.itk.org/pipermail/insight-users/2002-May/000427.html

Thanks for your help Luis, if all the above is impossible it's not a 
problem, I'm just curious - this toolkit is amazing,

Thanks,
Michael


>From: Luis Ibanez <luis.ibanez at kitware.com>
>To: Michael G <michaelguiliametti at hotmail.com>
>CC: insight-users at itk.org
>Subject: Re: [Insight-users] some information on the registration example 
>methods
>Date: Wed, 03 Mar 2004 20:19:05 -0500
>
>
>Hi Michael,
>
>
>It is great to have users who
>post messages when things work   !   :-)
>
>
>--
>
>
>About the deformable registration example,
>You can reduce the computation time by
>using a Multi-Resolution approach. This
>particular example is using the Demons
>algorithm and was implemented by Lydia Ng
>at Insightful. The DemonsRegistrationFilter
>derives from the generic class:
>
>     PDEDeformableRegistrationFilter
>http://www.itk.org/Insight/Doxygen/html/classitk_1_1PDEDeformableRegistrationFilter.html
>
>
>The MultiResolution variant of this class is the
>http://www.itk.org/Insight/Doxygen/html/classitk_1_1MultiResolutionPDEDeformableRegistration.html
>
>What you want to do in this case is to progressively
>refine the deformation field by computing first a
>low resolution version of it. In this way you reduce
>the time to convergence and improve the robustness
>of the registration.
>
>
>You will find information on the ITK registration
>framework in the Software Guide:
>
>     http://www.itk.org/ItkSoftwareGuide.pdf
>
>In particular Chapter 8.
>
>(you can order the paper version of this document
>from Amazon.com and from Kitware's estore)
>http://www.kitware.com/products/itkguide.html
>
>
>You will also find details on the theory behind
>algorithms implemented in ITK, in the book
>"Insight into Images" published by A.K. Peters
>http://www.akpeters.com/book.asp?bID=206
>
>
>The tutorial session on deformable registration
>presented by Dr. James Gee will also be illuminating:
>http://www.itk.org/CourseWare/Training/NonRigidRegistrationMethods.pdf
>
>
>
>
>Please let us know if you have further questions.
>
>
>
>   Thanks,
>
>
>
>     Luis
>
>
>
>------------------------------
>Michael G wrote:
>
>>Hello,
>>
>>I am using the technique in ImageRegistration1 to motion correct a set of 
>>dicom images and it's working great. It takes about 3-4 seconds per image.
>>
>>I noticed the other great examples, specifically the 
>>DeformableRegistration2, because it seems to offer even cleaner results. 
>>This method is taking a great deal longer to run per slice, around 11 
>>seconds on the same machine.
>>
>>Are there any methods to improving the speed for these methods? Also are 
>>there more resources on the science behind these registration methods that 
>>itk has provided for us? I could only find
>>http://www.itk.org/CourseWare/Training/RegistrationMethodsOverview.pdf
>>
>>Thank you very much for any info,
>>Michael
>>
>
>
>
>_______________________________________________
>Insight-users mailing list
>Insight-users at itk.org
>http://www.itk.org/mailman/listinfo/insight-users

_________________________________________________________________
Fast. Reliable. Get MSN 9 Dial-up - 3 months for the price of 1! 
(Limited-time Offer) http://click.atdmt.com/AVE/go/onm00200361ave/direct/01/