Hello ITK community,
I’m trying to understand how BSpline grid is defined over two images during a multi-resolution registration process. I just need the confirmation for the following thoughts:
- BSpline grids are uniform grids, so for example if I have an image 200mmx200mm, then I define a four stage multi-resolution 128,64,32,16mm as the pyramid, the number of grid points for the coarsest resolution (128) would be 1. I saw in the code that Spline Order is added to this (1+3=4) that makes 4 grid points uniformly split the 200x200 image. Is this correct? or the grids are non-uniformely split the image? I’m wondering where exactly 3 other control points are located?
- what happens if you have an image 100x100mm then you define 128mm grid size? does the code only consider 3 number of points to split the image?
These might be low level details, but I appreciate if someone could help me figure this out.