[Insight-users] invert deformable field

[Corinne Mattmann]

Hi,

I would like to predict a future deformable field from several fields
from the past. It is not too difficult to calculate the future shift in
a pixel by going through the deformable fields, taking always the
closest point (as a first approach). But then I just have the vector
where I have to shift this pixel intensity to ("forward field"). However
to use the warpImageFilter and to actually apply this field I need a
"backward field". Therefore I have to invert the field I get.
I tried using the DeformationFieldInverseImageFilter (is this what I
need?) but I had to use a subsampling factor of 6 (for a 50x50x50 image)
to get an acceptable speed which is not at all accurate enough for my
images. When I chose a smaller value (4), the program crashed.
Do you have any ideas how else I could get an inversed deformable field?
Or is there even another possibility to predict a deformable field from
several others?

Thanks very much,
Corinne