The standard in linear registration is the use of resolution pyramids to cover also 'long-range' transforms. The multi-resolution registration should provide a more robust solution than the single-resolution (current state).
The implementation is straightforward by:
- change RegistrationType from itk::ImageRegistrationMethod to itk::MultiResolutionImageRegistrationMethod
- add a new observer for conrolling parameters on pyramidal scale change
- adapt the value presents in the .xml configuration file