[Insight-users] optimizer

[Luis Ibanez]

Hi Bing,

The LevenbergMarquardtOptimizer is intended to be used
with metrics returning an array of values instead of
a single value. That is, with multi-valued cost functions
instead of single-valued cost functions.

None of the current image metrics in ITK returns multiple
values, all of them are single valued. Therefore the
LevenbergMarquardtOptimizer is not appropriate for them.

One typical use of the LevenbergMarquardtOptimizer is
in the implementation of ICP (Iterative Closest Point).
Julien Jomier at UNC-CADDLab is currently developing
such implementation.  In this case, the metric values
provided to the optimizer are all the distances between
points in one set and the closest points in the other
set.


Regards,


    Luis


-------------------
Bing Jian wrote:
> Hi, Luis,
> 
>   I noticed that LevenbergMarquardtOptimizer
> is subclass of MultipleValueCostFunction while
> ImageToImageMetric is based on SingleValueCostFunction.
> So there is no way to use LevenbergMarquardtOptimizer
> directly in the ITKRegistration framework at the moment,
> right?
> 
>   Thanks!
>