Which GUI component are you referring to? If you are referring to the RegistrationPointDataAquisition, it does not have functionality to set points.
You can obviously modify it to support this functionality. Possibly something like the PointDataAquisition’s set_point_indexes. To convert from physical points to continuous indexes you will need to use the TransformPhysicalPointToContinuousIndex for each of the two images.
I am trying to write a method set_point_indexes, in RegistrationPointDataAquisition. However, I am getting the following error while calling TransformPhysicalPointToContinuousIndex.
TypeError: in method 'Image_TransformPhysicalPointToContinuousIndex', argument 2 of type 'std::vector< double,std::allocator< double > > const &'