I wrote this OpenCV port for Xojo 5 years ago. At that time, OpenCV was 32-bit and offered about 600 functions written in C and easily accessible with Xojo. OpenCV is now 64-bit and written mostly in C++. Many C functions are obsolete. Last week I looked into whether OpenCVX could be upgraded to 64-bit, but without success. Unfortunately I don’t have time to interface Xojo with a complex C++ library.
You can use this library Pandore: a library of image processing operators which is easily accessible from the command line. It is a series of simple chainable operators that can be called with Xojo. You can also use the OpenCV python version.