I installed the itk and i found that this file is not installed
itkSimpleFuzzyConnectednessScalarImageFilter.h
I read that it is a patented algorithm and there migh be a directory for patented algorithms
but i do not find it. So can i add this file from somewhere else?.
No, because ITK uses Apache license since version 4. Apache license can only be used for code which is free to use (no patent licencing fees). And patent right holders want to charge fees, as that is the main goal of patenting something.
So that code can be added only after the patent has expired.