Dear SPM experts,

This may sound like a dumb question, but how does spm5 warp images
with displacement fields, such as those derived from an _sn.mat file?
I have looked at the code but would be really grateful if someone
could say a few words about the subject.

The reason I ask is that I'm trying to get an average deformation from
several different deformations. I read in displacement fields and take
the average. This mostly works except but I apply the average
deformation to an image I get a result that is to my eye the correct
shape but shifted and rotated.

Has anyone here tried doing something similar? If so how did you go about it.