[Insight-users] registration: time-consuming metric

[Henning Meyer]

May thats a good point to ask my question regarding
BSplineDeformableTransform again:
Why do we need to optimize the support points of the BSplineGrid?
As far as I observed it is fine to keep them at zero.
Reducing the number of parameters would make optimization a lot easier
(e.g. less steps).
Is there an easy way to get rid of the parameters of the
support-Points in the BSplineGrid?

I tried implement an own version of BSplineDeformableTransform, which
is just using BSplineInterpolateImageFunction in TransformPoint. But I
don't know how to handle GetJacobian correctly. Actually my calculus
knowlegde is to low to handle this. Would it be fine to just skip the
weight, which are ouside of the grid-image?

Henning