[Insight-users] LBFGS with Centered2DTransform: All points mapped to outside of the moving image

[Luis Ibanez]

Hi  Felix,

Thanks for the clear description of the problem.

If the Exception is thrown before printing the first
iteration of the optimizer, it is then likely that the
problem is in the initialization of the transform.

...

Printing out the parameters that are received
by the Metric in its first evaluation will help
answering the question.

Simply add a std::cout in the GetValueAndDerivative()
method, of the Metric that you are using.


   Please let us know what you find,


        Thanks


             Luis


---------------------------------------------------------------
On Wed, Sep 30, 2009 at 9:39 AM,  <Felix.Bollenbeck at iff.fraunhofer.de> wrote:
>
> Dear ITK user,
>
> I want to use the LBFGS for centered 2D registration, instead of gradient
> descent, hoping for a little speed-up.
>
> I exchanged the optimizer in one of the multi-res examples.
>
> (The regular step gradient optimization works fine. )
>
> The LBFGS version complains though:
>
> "All points mapped to outside of the moving image"
>
> I assume, I have made two possible errors:
>
>
>         1. Scales are not passed correctly to the LBFGS and back, so that
> the floating image is indeed way off course
>
>
> and /or
>
>         2. Transform and/or Metric do not deliver derivatives as the
> optimizer expects it, and the registration method assumes that these values
> are zero
>
>
>
> The exeception is thrown before any optimizer positions are printed.
>
> Can you point me in the right direction?
>
> Regards,
>
> Felix.
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