SSD metric for affine alignment

[GFleishman]

I wasn't sure if there was a more appropriate place for this question.
Has anyone implemented a SSDMetric like object appropriate for use in affine registration?
I'm familiar with align.metrics.SSDMetric, but as far as I can tell, its API is not consistent with the requirements of align.imaffine.AffineRegistration.
Of course there is also align.imaffine.MutualInformationMetric but for my application, I need to very quickly affine align a very large number of 3D images and mutual information is just too slow. My images were all collected on the same instrument, and I've validated SSD as a suitable metric for affine alignment using other packages, though these are unfortunately all compiled C++ packages and thus don't integrate well with the remainder of my python software stack.
If there really is nothing like this in dipy, I would consider building it myself, but I don't want to start if something is already there.

[skoudoro]

Hi @GFleishman,

Thank you for asking. we have an implementation of SSD in one of my branches. It just needs cleaning and redesign because there is a lot of duplicated code (the current code is ugly, sorry for that)

You can look:

• here and here for the SSD code
• here for an example.

Do not hesitate if you have any questions and I will appreciate any feedback.

its API is not consistent with the requirements of align.imaffine.AffineRegistration.

Yes, we have a lot of work on this part. This is on our TODO list