Hi, After reading the wiki and the references on the wiki, specifically [1] and [2], I'm still a little confused about how the inflation and registration to a sphere occurs. ie. what energy functions are being minimized at each step.
I think it is a 3 step process, where
1. Surfaces are inflated by minimizing the energy function Js. This creates ?h.inflated. Js = 1/2V (EE ||xi-xn||^2) + lambda-d*Jd (8) in [1]
2. The inflated surfaces are then projected to a sphere by minimizing the energy function J. This creates ?h.sphere J = ???
3. The sphere is registered to the average by minimizing the energy function J. This creates ?h.sphere.reg. J = Jp + lambda-d*Jd + lambda-a*Ja (5) in [2]
Is there a step I am missing? Are my energy functions correct?
thanks, mishkin
[1] Cortical Surface-Based Analysis II: Inflation, Flattening, and a Surface-Based Coordinate System, Fischl, B., Sereno, M.I., Dale, A.M., (1999). NeuroImage, 9(2):195-207.
[2] High-resolution inter-subject averaging and a coordinate system for the cortical surface, Fischl, B., Sereno, M.I., Tootell, R.B.H., and Dale, A.M., (1999). Human Brain Mapping, 8:272-284(1999).