I tried it with a Matlab function block:
function centers = fcn(image)
centers = imfindcircles(image,30);
and got the Coder Error:
The function 'imfindcircles' is not supported for standalone code generation. See the documentation for coder.extrinsic to learn how you can use this function in simulation.
Thank you very much in advance and merry christmas and a happy new year.