[Insight-users] Re: Performance change in registration between ITK 1.8 and ITK 2.0

[Luis Ibanez]

Hi George,

Thanks for letting us know about your performance test.


I assume that you are compiling your code for Release...
is that right ?

Is there a chance that you could share that test with us ?
That would help us to locate the potential source of
performance change.



One potential suspect is the recent modification of one
method of the interpolator in order to support the 3D/2D
registration with the ray cast interpolator.

This modification involved to make some methods "virtual".
This could have resulted in the peformance degradation
that you are observing.


You may easily verify this hypothesis by reverting the
change and rerunning your performance test.

The change was in

   Insight/Code/Common/itkImageFunction.h


http://www.itk.org/cgi-bin/viewcvs.cgi/Code/Common/itkImageFunction.h?root=Insight&sortby=date&r2=1.35&r1=1.34

This was related to Bug # 1160.






Please let us know what you find.


    Thanks


       Luis




-----------------------------
Li, George (NIH/NCI) wrote:

> Hi, Luis and all users:
>  
> I have done a little performance testing between ITK2.0.0 and ITK1.8.0.
> Unfortunately, using ITK2.0.0, a registration work is about 20% slower.
> I don't know if anyone else have experienced this.
>  
> Here is what I did. My code is to do 3D image registration using Mattes
> metric, evolutionary optimizer, and Versor3DTransform. For fixed 500
> iterations, it took 60 seconds using ITK2.0.0, while it took 48 seconds
> using ITK1.8.0. These numbers are average of three runs with the same
> two images on the same machine under identical conditions.
>  
> This is just to post a concern about the performance, and hopefully, it
> would not become a trend for future release. Usually, I would have to
> iterate 10,000 times for a good registration, which is consistent with
> what in Martin Styner's paper. If my program were used in clinic, to let
> users wait another 20% more time after a new release, they probably
> would rather stay with the old version. That is reality.
>  
> Thanks for all the work to keep ITK growing.
>  
> Regards,
>  
> George
>