C interfaces will not come back. they were removed deliberately.
if you need something with a C interface, look into OpenVX.
or consider writing a wrapper. the python bindings are a wrapper (automatically generated… but from custom code) that primarily translates between cv::Mat and numpy matrices. it’s basically C++ code that uses OpenCV and presents C functions that extend python. I’m sure you could do something similar.
I can’t believe that Delphi wouldn’t have gained some way of interfacing with C++ libraries… what is this?
this looks like you’ll have to use C++ Builder to build OpenCV, because you’d need C++ Builder for this type of compatibility.