===== 4D registration =====

I didn't know this plugin made in 2005 for registration of 4D:

PoorMan3DReg
A poor man's 3D registration plugin for aligning dynamic 3D volumes.
http://sybil.ece.ucsb.edu/pages/poorman3dreg/index.html

I only went to the bottom figurem but looks like a good plugin for 4D registration. I will check further. The author seems to be reserved from making it too famous because of other registration plugins available in ImageJ. I think, contrary to the authors view, such 4D availability has not been around.