[Insight-users] MultiResolution registration

[Luis Ibanez]

Hi Jesse,


When you use MultiResolution, it is convenient
to set a very large number of iterations in the
coarsest level as well as a small learning rate.

Don't care much about the subsequent resolution
levels until to succed to get convergence in the
coarsest level.

Once you get the first level to converge (that
is, to stop before using all the allotted
iterations), play increasing the learning rate
and decreasing the number of iterations for this
coasest level. The goal is to get it to converge
using the largest possible learning rate.
This will result in the shortest convergence time.

Once you have done this tunning for the coarsest
level, you can keep the parameters for this level
and start doing the same tunning on the next
resolution level.



Regards,


  Luis


-------------------
iajesse wrote:
> Hi Luis,
>  
> The output file is ok now, but another question occur.
>  
> Now, There are 30 patient dataset, each patient have  T1 and T2, I want 
> to register the T1 to T2,  and apply MultiResMIRegistration  on them, 
> but about 10 patients are misaligned, I tune some parameter, such as: 
> The number of iterations, learning rate , but improvement is little. 
> Could you please give me some advice on how to tune parameter? for 
> example, which parameter should be changed first?
>  
> Thanks
>  
> Jesse
> 
> */Luis Ibanez <luis . ibanez at kitware . com>/* wrote:
> 
> 
> 
>     Hi Jesse
> 
>     The ITK terminology for registration has changed over time.
> 
>     In the early days we used to talk about "target" and "source"
>     image. Then we switch to "fixed" and "moving" which are the
>     terms used today, and is how you will find the descriptions
>     in the software guide.
> 
>     This application is one of the earliest on the toolkit and
>     it is therefore making use of the original terminology in
>     some sections.
> 
> 
>     If you look at the code of the application
>     (Ah, the pleasure of open source !), you will see in:
> 
> 
>     InsightApplications/MultiResMIRegistration/Common
> 
>     SimpleAppOutput.txx
> 
>     That the correspondences are:
> 
>     "target" ----> "fixed"
>     "source" ----> "moving"
>     "register" ----> "resampled moving"
> 
> 
>     Please find attached a modified version of this file
>     that will save the images as M! etaImages instead of
>     series of PGM files. MetaImage use a text header file
>     and a binary raw data image file.
> 
>     Use it to replace the one in your system. In that way
>     you will not need to go through the extra step of using
>     Mricro for viewing the images.
> 
> 
> 
>     Please let us know if you find further problems.
> 
> 
>     Regards,
> 
> 
>     Luis
> 
> 
> 
> 
>     ------------------------
>     iajesse wrote:
>      > Hi Luis,
>      >
>      > I have a problem on output of MultiResMIRegistration ,
>      >
>      > There are three dataset in ourput,
>      >
>      > register000.pgm ....
>      > source000.pgm,,,
>      > and target000.pgm ...
>      >
>      > I convert them into raw image using Mricro, but find that the new
>     target
>      > image is not the old one, and source is not the old one. I think
>     that
>      > the target is the fixed, and source is floating, why target change?
>      >
>      > Best
>      >
>      > Jesse
>      >
>     =========================================
> 
>