[Insight-users] Kernel Transform issues

[Luis Ibanez]

Hi Gary,

How many landmark points were you passing to the ElasticBodySplineKernel
Transform when you notice these artifacts in the image resampling ?




About the registration issue that you report: that the final parameters
are the same as the initial ones, that looks more like an optimizer
issue, than an issue related to the Transform.

+ What optimizer were you using for those trials ?
+ How many iterations of the optimizer did you run ?
+ Did you plotted the values of the Metric at every iteration of
   the optimizer ?
+ Were those values of the metric changing significantly ?




Please let us know,



Thanks


   Luis

-----------------
Gary Kline wrote:
> We have been developing some software based on ITK, and ran into some 
> problems with some of the kernel transforms.  In particular, the elastic 
> body spline kernel transform, when applied to an image, was introducing 
> a lot of noise into the transformed image.  Depending on the input 
> image, the noise took the form of “speckle” noise, or lines in the 
> output image.
> 
>  
> 
> Has anyone else run into this problem?
> 
>  
> 
> The other problem we have run into is trying to use the elastic body 
> spline kernel, or the elastic body reciprocal spline kernel, in image 
> and point set registration applications.  When we use either of these 
> two kernels, the final parameters reported after the registration 
> process are the same as the initial parameters.  We do not have this 
> problem using the other kernel transforms.
> 
>  
> 
> Has anyone else seen this problem?
> 
>  
> 
> We are currently using both Windows with VS.NET 2003, and Linux with gcc 
> 3.4(? – working from memory, my VM is not running).
> 
>  
> 
> Thank you,
> 
>  
> 
> Gary Kline
> 
> AccuSoft Corp.
> 
>  
> 
> 
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